Date: Tue, 1 Oct 1996 08:33:22 -0500 From: Les Subject: Radio Shack Voltmeter? Still working on setting up a seismograph here in bedrock, Alabama...It looks like I may purchase a system or parts of one from Larry Cochran. Thanks to all who've responded with advice. Next question...Has anyone ever used the Radio Shack logging DVM for seismograph applications? It seems to just be a basic AD converter with some software included. It retails for around $120 but I've seen it on sale here for less than $100. Les Rayburn, KT4OZ Les Rayburn http://www.phpad.com/whitley New Machine: The Chris Whitley Website +++++++++++++++++++++++++++++++++++++++++++++++++++ Home: (205) 980-8332 Work: (205) 324-3900 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) Date: Tue, 01 Oct 1996 10:21:16 -0500 From: ct@....... (Charlie Thompson) Subject: Re: Radio Shack Voltmeter? Les, One reason not to consider the Radio Shack approach is the lack of time/date stamp on the recorded data. If you don't have time info you don't have a way to correlate your events with the rest of the world. My recommendation is to go with something that allows you to share data files with everyone else. SDR and WinQuake are hard to beat! Regards, Charlie WB4HVD _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: cochrane@.............. Subject: Vancover Island Region Ms 6.3 event and uploading event files Date: Mon, 07 Oct 1996 14:23:22 -0700 Hi There, The Vancover Island Region had a Ms 6.3 yesterday (10/06). Both my SG sensor and Lehman sensor recorded nice seismograms of the event. I updated the following web page at http://psn.quake.net/teleseis.html with links to my event files. If anyone recorded the event this would be a good time to try a new email feature I added to my system. You can now upload/send PSN formatted event files using email. If you attach a PSN formatted event file in a email message to event@............. your event file will automatically be archived on my system. The event file must be encoded using MIME. This is the most efficient way of sending binary files using email. If you have a popular email program that does not have the ability to send attachments in MIME format let me know and I can try and add other formats like uuencode or BinHex. Too upload one or more event files all you need to do is attach the file(s) and send it to event@.............. The subject line and the body of the message are currently not used so can be left blank. When my system receives the email message it will decode the message and archive your event file(s). My system will then send back a email message acknowledging your upload. All event files uploaded using this method will have the name of the file normalized by using the date in the header and placed in the appropriate sub-directory. The directory location is based on the year and month (/quakes/YYMM/). The file name will have the following format: YYMMDDx.SID where YY=year MM=month DD=day and x is the letter A-Z. The first file uploaded for a given day will start with YYMMDDA.SID the next file would be YYMMDDB.SID etc. The .SID is the station ID. By sending your event files using this method your event file will show up on both the finger quake@............. list and the "New Earthquake Event Files" (http://psn.quake.net/cgi-dos/event.exe) on my PSN Web site. In the future I hope to add the ability for my system to send back MIME encoded event files (and other program files) by placing a get or send command and a list of files in the body of a email message. I could also setup another mailing list, say newevents@.............. that could be used to automatically inform the members that a new event file(s) has been uploaded. Let me know if you have any problems using the event@ mailbox. Regards, Larry Cochrane Redwood City PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: My quake files Date: Wed, 09 Oct 1996 13:19:11 -0600 Robert L Barns wrote: > The remnents of a tropical storm passed by here yesterday and dumped 2" of > rain. My seismic noise level went up by a factor of 6 or so. It is down > somewhat today. I suspect that all this noise was due to wave action on the > shore since I'm only 30 miles from the Atlantic. What do you think? The last > big rain we had was also accompanied by a noise level increase and I thought it > might be due to the ground getting wet. Skolnic sez that his noise changes from > fall to winter and then back again from winter to spring. The noise in the period range 5-10 seconds are called microseisms and are principally caused by ocean waves hitting the continental shelf. When I was a gradute student at Lamont-Doherty Geological Observatory of Columbia University near New York, we would see the microseism level on our seismographs increase in the winter, particularly when there were storms off the Atlantic coast. Several papers have been written on the subject with respect to locating the "source region" and using the noise as a means of comparing the site response of adjacent sites. Pretty sharp of you all to come to similar conclusions yourselves. -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ct@....... (Charlie Thompson) Subject: Re: My quake files Date: Wed, 09 Oct 1996 14:46:17 -0500 As luck would have it...my computer was DEAD for the 6.3Ms Vancouver event. Got it fixed last night and (as luck would have it again!) I captured the smaller Vancouver 5.3Mb event of 10/9/96 at 7:12:28 UTC. My seismic noise level is high for some reason as well (re: Robert Barns comment) so you can't make out the P and S of this smaller event. As usual I cheated, used my GPS to calculate the distance from Buda, and set the P and S spacing so the distance was correct and then moved them as a pair until the origin time was correct. I then turned on the PHASES mode to see if the easily visible L wave was in the correct place. I'll try out the new event@ mailing address and upload this smaller Vancouver event. -Charlie Thompson Buda, Texas ct@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: My quake files Date: Wed, 09 Oct 1996 18:20:13 -0700 Hi, Unfortunately this won't work. You must use a email program that can do the encoding and make the proper message needed for attachments to work. Just sending a text file with the encoded message will not work. If you are running Windows I would recommend using Eudora Light or Pro. The Light version is free and is one of the most used email programs. The Pro version costs around $60.00 and has a few other features like a built in spell checker (something I dearly need). You can down load the free version from any Windows software archive. Eudora is very easy to setup and use. To send an attachment all you need to do is select Attach File and then click on the file to send. Now when you click on Send your file will be encoded and formatted so any email program (with the ability to handle attachments) can read and un-attach you binary file. Regards, Larry Cochrane Redwood City, Cal PSN At 02:36 PM 10/9/96 EDT, Robert wrote: >Larry, > I will try to send 2 of my quake files which are MIME encoded. I encoded >them with ENCODE64.EXE. and they will be sent to event@............. per your >instructions. > This prog. and its mate DECODE64.EXE were obtained from BASE64.ZIP at > http://sunsite.doc.ic.ac.uk/public/pub/packages/simtel-msd > Both run under DOS and seem very easy to use. This URL included to help others with MIME. > My file 1006.rlb was for the Vancouver quake. .... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ct@....... (Charlie & Terri Thompson -- Buda MicroRanch ) Subject: Question about Pendulum Modelling Date: Tue, 15 Oct 1996 08:44:00 -0500 I've been reading the Shackelford-Gunderson material thats available on the PSN page and had a few questions about what's going on with this type of sensor and particularly the electonics associated with the S-G sensor. Firstly, Am I correct in assuming that a pendulum has two modes of sensitivy? 1. Above the natural frequency: it acts like a displacement sensor 2. Below the natural frequency: it acts like an accelerometer. If this assumption is true then the roll-off in frequency response below the natural frequency must be 2nd order or 40 dB per decade or 12 dB per octave (if you prefer octaves). I am getting the 2nd order notion from the fact that the pendulum can be equivocated to a spring-mass oscillator which is a 2nd order system. Also note that the difference in displacement and acceleration is a "double derivative". Seems like we might be able to characterize the pendulum's response and "build a better equalizer" in the DSP domain giving a flat displacement response from say 60 seconds to 20 Hz. What puzzled me about the SG article was that the integrator used to boost the low end is only 1st order yet I think the rolloff in pendulum response is most likely 2nd order. Hence we can do better! Any comments, corrections, appreciated. Regards, Charlie Thompson Buda Seismic Station ct@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Larry P. Thomas WAOGWA" Subject: Re: Question about Pendulum Modelling Date: Wed, 16 Oct 1996 07:25:57 -0500 I'm confused! I was just about to make up my mind which type of seismometer to build and then got confused. Maybe some could help unconfuse me so i can go on and build my sensor. I had initially convinced myself to that I should build a Shackleford-Gundersen design because I want mostly teleseismic activity monitoring and thought it would be the best because of it's long period. I dug out an old physics book (two kids, four grand kids ago!) and looked up pendulums and of course saw that the period is related to pendulum length and gravitational force. The restoring force gravity acting on the mass, etc. etc. This got to thinking that the Lehman design should have a longer time period than the Shackleford-Gundersen design because the Lehman design has an effective pendulum length that is very long. I'm looking at the arc that the mass swings through as an indicator of effective pendulum length. My first thought was to pick the mechanical system that was the best and then use the sensor/detector electronics that I thought was best. I'm wondering now if the Lehman mechanical design with the Shackleford-Gundersen RF detector scheme as the business end would not be the best. It seems that the signals from the magnet/coil detector configuration are just too low an into the noise floor for teleseismic. From an electronic standpoint I kind of like the RF detector scheme used in the Shackleford-Gundersen design and no reason it would not work well with the Lehman mechanical structure. If anyone has time to respond I gladly share the results of any work I do on a sensor using part of both designs. Thanks Larry --------------------------------------------------------------------------- Larry P. Thomas wa0gwa voice : 1 913 888-0282 Krell Technologies fax : 1 913 782-9359 8960 Bond pager : 1 816 989-HELP Overland Park, KS 66214-1764 e-mail : lpthomas@................ --------------------------------------------------------------------------- _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ct@....... (Charlie & Terri Thompson -- Buda MicroRanch ) Subject: Re: Question about Pendulum Modelling Date: Wed, 16 Oct 1996 08:31:32 -0500 >I'm confused! I was just about to make up my mind which type of seismometer >to build and then got confused. Maybe some could help unconfuse me so i can >go on and build my sensor. (other text deleted) Larry, You are exactly right about the pendulum periods. I like your idea about the RF detector on the Lehman pendulum! I've built a Lehman and have the period set at about 10-14 seconds. It's very easy to build a Lehman and common sense changes to the original design work fine. You can look at my sensor at: http://www.onr.com/user/ct/ct.html I have a couple of photos on the above URL. Also at the bottom of photo #1 is a seismogram the sensor recorded of a teleseismic event in the Easter Islands. Another important difference between the coil/magnet and the RF pickup response is the "1st derivative". That is, the voltage in the coil is proportional to the RATE OF CHANGE of POSITION (pendulum velocity) or what we call dPhi/dT in EE terms. There's only one sticky part...you must power the RF oscillator by connecting very fine wires which will flex with the Lehman pivots. I propose getting around this problem by the following diagram. (Note: use a fixed-pitch font to correctly view the following diagram:) __________ | | <----- pair of plates on pendulum shorted at top | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | <---- Staionary sense plates A and B | | | | A | | B C D <------ Stationary driven plates C and D The scheme allows both the driven and sensed plates to be stationary. As the pendulum moves you couple, for example, from driven plate C to the moving pair which are electrically shorted and then to sense plate A or B. The sense plates can still be double sided PC board with the outside layer gounded to help form the resonating cap in parallel with the inductor. Any comments, suggestions, concerns? regards, Charlie Thompson ct@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Re: Question about Pendulum Modelling Date: Wed, 16 Oct 1996 11:50:42 -0700 Greetings -- Yes, I believe you are right that the pendulum system is second order. I worked out some equations and you're right -- it boils down to a second-order differential equation. Since my differential-equation solving abilities leave a lot to be desired, I modeled it using a spreadsheet with a delta-time for each step that is small compared to the resonance period of the pendulum or the period of earthquakes. It did show second-order response with respect to earthquake waveform period. Jim Hannon wrote -- >I have a good model for >the pendulum, sensor and of course the support electronics but I am stumped >on how to represent the feedback from the coil/magnet to the pendulum. >I can't seem to come up with a circuit that would act like the real system. >Anybody have any ideas? If I can get the Spice model working the response, >damping and stability can be studied. The force from an electromagnet is more or less proportional to the current through it. I'm no magnetics expert, but I think the linearity of the B-H curve (and eventual saturation) of any core you might be using for the coil will be a factor too. I believe this is why most magnets like this (ie. speaker coils) are air-core devices. I don't have any good ideas on how to do a Spice model for the non-linear behavior of any core you might be using. I think that your Spice model should also include the dc resistance as well as the inductance of the electromagnet coil. I think if you intruduce a small-value shunt resistor in your model in series with the coil to sense current, then amplify the voltage across the resistor by a factor related to the geometry of the coil and the strength of the permanent magnet (use the calibration device described by Robert L. Barns earlier on this list to measure the current-to-force relationship), you'll have a parameter (voltage or current) in the Spice model proportional to the force on your mass. Since F = Ma, and displacement is the double integral of acceleration, you can run this voltage (or current) through two electronic integrators (Spice models) in series, and then feed it as a current to your mass capacitor (I'm assuming you're modeling the mass as a capacitor). Since in a capacitor, i = C * dv/dt, your capacitor's dv/dt will be equivalent to dx/dt (velocity) for a real mass, and the voltage on the capacitor will be equivalent to displacement of a real mass. I've done some computer modeling (not using Spice) of the force-balance system I'm working on and it seemed to work quite well after I adjusted the roll-offs of the various stages. I've yet to try the real thing, though. I hope this helps. Please ask more questions if I can help more. -- Karl Cunningham karlc@......... La Mesa, CA. 116.9775W 32.7705N +308M interested in almost anything to do with science _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ct@....... (Charlie Thompson) Subject: Guatemala Quake detected Date: Wed, 16 Oct 1996 17:04:00 -0500 Looks like I recorded a somewhat noisy but discernable waveform from the Guatemala Coast 4.9 that occurred at 8:42 UTC 10/16/96. I need to check the distance estimate to make sure I have the P/S marked correctly and I'll upload it. Did anyone else record this quake? I know it's not big one but Texas is not too far from Central America. Charlie ct@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Warner Lindholm Subject: Re: Question about Pendulum Modelling Date: Thu, 17 Oct 1996 07:08:09 -0700 (PDT) On Wed, 16 Oct 1996, Jim Hannon wrote: [ ..... ] > As for the rolloff compensation of the Shackleford-Gundersen design I think > there is another rolloff here that needs to be considered. It runs in the > other direction so it might cancel out with the instrument. That is I think > the seismic waves themselves have higher displacments at the lower ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > frequencies. This may cancel with the remaining rolloff of the sensor. ^^^^^^^^^^^^ This has been my observation using the fft feature of Larry Cochrane's Winquake on records obtained with a sensor sensitive to displacements ( and tilt). I think seismic noise might be 1/f just as many other natural processes are. -Warner > (Someone correct me if I am wrong.) > > Jim Hannon > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Question about Pendulum Modelling Date: Thu, 17 Oct 1996 12:09:43 -0600 Warner Lindholm wrote: > > On Wed, 16 Oct 1996, Jim Hannon wrote: > > [ ..... ] > > > As for the rolloff compensation of the Shackleford-Gundersen design I think > > there is another rolloff here that needs to be considered. It runs in the > > other direction so it might cancel out with the instrument. That is I think > > the seismic waves themselves have higher displacments at the lower > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > frequencies. This may cancel with the remaining rolloff of the sensor. > ^^^^^^^^^^^^ > This has been my observation using the fft feature of Larry Cochrane's > Winquake on records obtained with a sensor sensitive to displacements > ( and tilt). I think seismic noise might be 1/f just as many other natural > processes are. > -Warner > > > (Someone correct me if I am wrong.) > > > > Jim Hannon > > > > Subject: Re: My quake files Date: Wed, 09 Oct 1996 13:19:11 -0600 From: Edward Cranswick Organization: US Geological Survey To: PSN-L Mailing List References: 1 >Robert L Barns wrote: >> The remnents of a tropical storm passed by here yesterday and dumped 2" of >> rain. My seismic noise level went up by a factor of 6 or so. It is down >> somewhat today. I suspect that all this noise was due to wave action on the >> shore since I'm only 30 miles from the Atlantic. What do you think? The last >> big rain we had was also accompanied by a noise level increase and I thought it >> might be due to the ground getting wet. Skolnic sez that his noise changes from >> fall to winter and then back again from winter to spring. >The noise in the period range 5-10 seconds are called microseisms and >are principally caused by ocean waves hitting the continental shelf. >When I was a gradute student at Lamont-Doherty Geological Observatory of >Columbia University near New York, we would see the microseism level on >our seismographs increase in the winter, particularly when there were >storms off the Atlantic coast. Several papers have been written on the >subject with respect to locating the "source region" and using the noise >as a means of comparing the site response of adjacent sites. >Pretty sharp of you all to come to similar conclusions yourselves. The microseismic noise exhibits a fairly sharp peak at about 7 s period (0.14 Hz), and at higher frequencies, it does have approximately a 1/f decay. -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: JAMES CRISTIANO Subject: QuakeAlert Date: Tue, 22 Oct 1996 14:57:52 -0700 Anyone hear about a new device called "QuakeAlert"? It's made by a place called Tectonics Reaserch Group, Inc. up in Canada. Haven't received my sample and info pack yet. I got a fax with some info on it. The maker claims that it senses only seismic generated "P" waves and turns on a loud alarm to provide early warning of an earthquake. If anyone knows anything about it please r.s.v.p. Thanks, James Cristiano P.S. Sorry bout that Larry, I'm new a this and I didn't mean to YELL. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) Subject: Re: QuakeAlert Date: Tue, 22 Oct 1996 14:07:40 -0800 ... "QuakeAlert"? The maker claims that it senses only seismic generated "P" waves.... ***************************************************************** That's the problem. There is no way that this device can distinguish P-waves from any other source of vibration! I saw something like this a few years ago and it was a novelty item, not a useful warning system. JCLahr ################################# John C. Lahr ################################ U.S. Geological Survey ############################### c/o Geophysical Institute ############################## 903 Koyukuk Drive From: ct@....... (Charlie Thompson) Subject: Effects of temperature on Lehman Sensor Date: Wed, 23 Oct 1996 13:10:28 -0500 Well believe it or not it has actually cooled off here in Texas. My Lehman sensor in the last few days has shown very high 1/f noise levels. I believe this to be associated with the fact that my PSN preamp is in the same insulated box with the Lehman sensor. Here's the theory as to why the noise level went up when the temperature went down: The preamp dissipates power. Normally it's pretty hot in the garage due to the Texas summer temperatures. Now that it's 50 degrees F in the garage the thermal currents from the "warm" preamp are making thermal air currents inside the sensor box. The air currents as we all know are bad news for noise levels as the currents push the Lehman boom around. Tonight I will remove the preamp from inside the Lehman housing and house it separately. Hopefully the air current noise will go down. My question to PSN readers is: Has anyone else experienced such conditions with fall approaching? thanks in advance, Charlie Thompson ct@....... Buda, Texas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lyzenga@................. (Greg Lyzenga) Subject: Re: Effects of temperature on Lehman Sensor Date: Wed, 23 Oct 1996 12:04:52 -0700 >My Lehman sensor in the last few days has shown very high 1/f noise >levels. I believe this to be associated with the fact that my >PSN preamp is in the same insulated box with the Lehman sensor. > >Here's the theory as to why the noise level went up when the temperature >went down: .. .. (stuff deleted...) .. >My question to PSN readers is: > >Has anyone else experienced such conditions with fall approaching? > Hi Charlie: I've been operating my Lehman now for about 6 years, and I continue to be totally BAFFLED by this problem. I have tried every possible permutation of preamp near the sensor vs. preamp near computer, etc. and I've never been able to make it go away. I hope you are more successful and can enlighten us! At the risk of boring you with a long narrative, I'll try to summarize my experience with this problem. For me (in southern California) the effect is definitely temperature related, but it is a time-of-day thing, rather than seasonal. Basically, my noise level is dramatically increased between the nighttime hours of about 10 pm and 10 am local each day. It always happens, although it tends to be worse during generally cold/wet weather and less severe when the weather is warm at night. One by one I have *tried* to eliminate all the possibilities for causes. I eliminated all sources of air currents in the sensor box - no joy. I tried putting the preamp close to the sensor and sending the amplified signal via 100 ft of wire to the house. I tried the reverse, sending the raw low-level signal via the long wires and amplifying in the house. These two seemed to give the same results. For a while, I felt that it was actual motion of the concrete floor in my garage, caused by thermal expansion and contraction, but lately I'm skeptical of that idea. Most recently, I have wondered if it is possible that some kind of temperature-dependent feedback could be driving an amplified noise current back through the pickup coil, causing the boom/magnet to move in response. I haven't really figured out how to test this hypothesis, except that I do not see any noise if the boom is physically restrained from moving. This may or may not support the theory. But I'm also skeptical about this because I don't really see much difference if the circuit is indoors or out in the unheated garage. (By the way, I should mention that my circuit is a homegrown beast, not the PSN design, so your mileage may vary!) I know it is *not* microseisms, because I pick those up routinely, and know that they are completely different from this. So after (apparently) eliminating all sources of mechanical, electronic, environmental and thermal disturbance, I'm about to go crazy trying to track it down! I would dearly love to figure it out, because if fixed, it would effectively double the amount of useful data I can record! You can imagine how frustrating it is to have a good teleseism come in during the night, only to find it drowned out by the nightly 10x increase in background noise. Although I don't have any solution at this point, I hope my experience might spark someone's imagination or insight into the phenomenon. - Greg |Gregory A. Lyzenga *** (909) 621-8378 |Dept. of Physics, Harvey Mudd College *** fax (909) 621-8887 |Claremont, CA 91711-5990 |http://www.physics.hmc.edu/profs/lyzenga.html _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ct@....... (Charlie & Terri Thompson -- Buda MicroRanch ) Subject: Temperature Sensitivity of Lehman sensor Date: Wed, 23 Oct 1996 23:26:05 -0500 Tonight I tried placing a 40 watt appliance light bulb in the box covering my Lehman sensor. I then monitored the noise level over the period of one hour. The noise was really reduced at one point and then went back up somewhat. This proved a definite relationship between interior box temperature and outside air temp. Larry's idea of "stuffing" the enclosure may be one way of reducing this "cold weather" problem. I also belive that air density at low temperatures, coupled with convection turbulence, is the cause of this noise problem. more later as I have time to experiment during the cool evening hours.... -Charlie Thompson ct@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: JAMES CRISTIANO Subject: HALL EFFECT Date: Thu, 24 Oct 1996 12:30:09 -0700 Sometime back someone suggested trying a hall effect sensor as the signal sensor for a seismic sensor. Having toyed around with the idea before and having samples, I got out the samples and data book. The samples are Allegro UGN3503U linear hall effect sensors. Specs are for a +6v regulated supply. Noise: 90uV Sensitivity: 1.72mV/gauss Using a push-push head-on magnet configuration with two Alinco 8, .212 Dia. x .187 magnets with .210 spacing produces a linear 8.44G change per .001" displacement. BOOM W/ MAGNETS <--------------------> N----S 1 S-----N 1 ___1___ sensor on base Since the sensitivity of the sensor is 1.72mV per Gauss and with the above setup the Gauss change per .001" is 8.44 then the output should be .014V per .001" displacement. Switching to metric I get .56V/mm. This signal is absolute displacement and not frequency sensitive. The problem I have with the coil/magnet setup is that the current induced in the coil by the magnet drops with decreasing frequency. With this method, the signal would be a copy of earth movement/displacement. The magnets could be mounted on the end of the boom and the sensor mounted on the base. Does this sound like it would be worth trying? Any ideas? James Cristiano weitech@.......... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: JAMES CRISTIANO Subject: Re: HALL EFFECT Date: Thu, 24 Oct 1996 14:18:29 -0700 RDJM@....... wrote: > > Jim, > > How much are the Hall effect sensors? Did you get free samples either through > yourself or your company? I have wondered how these would work. Thanks for > the info. > > Ron Moeller rdjm@....... Ron, I got the hall effect sensors as samples directly from Allegro. You can call them @(508)853-5000 and ask for a sample or two. It helps if you have a co. name to throw in. I called a distributor and the price was $1.42 (not bad). They include the data sheet also. The gal at Allegro said they have a new line ( 3506) that has higher sensitivity. I have a couple of those coming. Good Luck, Jim Cristiano _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Info: 1891 Nobi (Mino-Owari), Japan, earthquake Date: Thu, 24 Oct 1996 15:29:48 -0700 I am looking for information regarding of the 1891 Nobi (Mino-Owari), Japan, earthquake. Can some one refer me to some articles? --- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ACole65464@....... Subject: Thermal Effects on the Long Period Lehman Date: Thu, 24 Oct 1996 21:53:35 -0400 To Charlie and others effected by this problem, I had experienced problems with thermal noise on my long period horizontal instrument several years ago and it took me a long time to figure out if that was really the problem. To be certain that the instrument was being influenced by the air I disconnected the seismometer from the preamp. I shorted a 5K resistor to the first op-amp's input and to ground, then recorded the output signal during the usually bad times. The op-amps were OK in the preamp so the problem was with the seismometer. I already had a dust/draft cover over the instrument but it was not apparently adequate. The fix was a styrofoam box, 1" thick, use a drink cooler if you can find one large enough to go over everything. Certainly remove the electronics from the same enclosed space with the seismometer. Use a white glue like Elmers to glue the custom box together. Fill any gaps in the corners with fiberglas insulation then put duct tape over the gaps to prevent drafts from entering inside the box. Place this 5 sided box upside down over the instrument and then use duct tape to to seal off any small cracks between the cover and the concrete slab that the instrument is resting on. Thermal effects can contort the structure (building) attached to the concrete slab. I have read that people have sometimes placed a small electric lamp inside the styro box at the very top to ensure a more stable temperature. The thermal engine runs on warm air rising, coming into contact with a cooler surface then sinking again to the bottom. What is needed for our box are stratified layers of trapped air. If the exposed concrete slab is fairly temperature stable then the box temp will stabilize at that. Stryofoam is a great insulator. Buildings create a lot of thermal noise so it may be necessary to move the instrument tempoarily to another spot to see if that is the case. I hope this is usefull information, it helped me, and if this or something else worked better for you, then please tell us what the cure was. Allan Coleman _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: tblank@.......... (Ted Blank) Subject: Stratifying air in the enclosure Date: Thu, 24 Oct 1996 21:16:19 -0700 One of the professional sensors I inherited has a heater in the top of the enclosure to induce a stable gradient of temperature with hottest at the top and coolest at the bottom. If you are putting a light bulb inside the case/cover, I'd try putting it at the top. Even better would probably be a low wattage "flat" heat unit. Careful though, styrofoam is highly flammable. I wouldn't put a light bulb anywhere near sytyrofoam. (I really can spell...but this emulator doesn't have a ac...backspace key!) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L)) From: Al Allworth Subject: Re: Thermal Effects on the Long Period Lehman Date: Thu, 24 Oct 1996 22:59:13 -0700 At 09:53 PM 10/24/96 -0400, you wrote: >To Charlie and others effected by this problem, About the Lehman noise problem: I think I came on the list in the middle of this one, but have a few comments and questions. Are the coils provided with a Faraday shield to stop them from picking up external electric fields? If signals are picked up above the cutoff frequency of the filters, strange things can happen in the input stage. It is also possible for the input stage to go into oscillation with a large inductance (The coil) on its input. This might be controlled by the resistance of the coil which will be a function of temperature. What is the frequency of the noise? This is an interesting problem but not directly to my system. I am using Mark Products model L4 vertical seismometer. About the Hall effect pickup: This still doesn't measure displacement. It changes the time constant to that of the pendulum instead of that of the coil and input impedance. It does come closer to measuring displacement, though. Just a technicality. I think there are several advantages to Hall effect, one being its lower impedance. One possible negative effect might be any influence changes in earth's field during an EQ. I know people are measuring fluctuations in earth field and are trying to eliminate effects of movement in their systems. Here we are talking about the reverse effect. Interesting list. Al Allworth, Pasadena CA aallworth@........ ____________________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Al Allworth Subject: Re: Thermal Effects on the Long Period Lehman Date: Thu, 24 Oct 1996 23:00:16 -0700 At 09:53 PM 10/24/96 -0400, you wrote: >To Charlie and others effected by this problem, About the Lehman noise problem: I think I came on the list in the middle of this one, but have a few comments and questions. Are the coils provided with a Faraday shield to stop them from picking up external electric fields? If signals are picked up above the cutoff frequency of the filters, strange things can happen in the input stage. It is also possible for the input stage to go into oscillation with a large inductance (The coil) on its input. This might be controlled by the resistance of the coil which will be a function of temperature. What is the frequency of the noise? This is an interesting problem but not directly to my system. I am using Mark Products model L4 vertical seismometer. About the Hall effect pickup: This still doesn't measure displacement. It changes the time constant to that of the pendulum instead of that of the coil and input impedance. It does come closer to measuring displacement, though. Just a technicality. I think there are several advantages to Hall effect, one being its lower impedance. One possible negative effect might be any influence changes in earth's field during an EQ. I know people are measuring fluctuations in earth field and are trying to eliminate effects of movement in their systems. Here we are talking about the reverse effect. Interesting list. Al Allworth, Pasadena CA aallworth@........ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ct@....... (Charlie Thompson) Subject: Re: Stratifying air in the enclosure Date: Fri, 25 Oct 1996 09:56:57 -0500 I had a new clue on the Lehman thermal noise problem last night. I took the lid off the sensor housing for a few minutes and replaced it. I then covered the housing with plastic "moisture barrier" like the material used to seal out moisture in concrete slabs before pouring. I started SDR and the noise level was VERY LOW! I was pleased that I had solved the problem.....then....about an hour later the noise had slowly crept back up again to the same obnoxious levels. Here's what I believed happened: Opening the lid caused the air in the box to equalize in temperature with the outside surrounding air. After the lid was replaced the slab started heating the air at the bottom of the box...as more and more air in the box became heated the thermal covection currents started circulating again. My lid is NOT perfectly sealed. There may have been some heated air exchanging with cooler outside air via the cracks where the lid sits on the top of the housing. I will test this hypothesis again. If I can repeat the experiment we'll at least have a handle on the problem. My guess is that insulating the BOTTOM of the box from the heat-producing slab will help as well as hermetically sealing the lid in place. If that doesn't work I'll try the light bulb at the TOP this time. -Charlie ct@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: JAMES CRISTIANO Subject: Re: HALL EFFECT Date: Fri, 25 Oct 1996 11:47:53 -0700 Al Allworth wrote: > > About the Hall effect pickup: This still doesn't measure displacement. It > changes the time constant to that of the pendulum instead of that of the > coil and input impedance. It does come closer to measuring displacement, > though. Just a technicality. I think there are several advantages to Hall > effect, one being its lower impedance. One possible negative effect might be > any influence changes in earth's field during an EQ. I know people are > measuring fluctuations in earth field and are trying to eliminate effects of > movement in their systems. Here we are talking about the reverse effect. > > Al Allworth. Pasadena,CA aallworth@........ Al, I'm talking about a Lehman type, horizontal swinging mass without dampening and a microscopic return to zero. Correct me if I'm wrong, but isn't the idea of suspending an inertial mass on a hinge to decouple it from the earth and to provide a zero point from where measurements of earth movements are taken? The inertial mass of the weight stays in one place as the earth move back and forth. If a movement of 1mm/sec came through, the generated signal would be an offset displacement signal in real time with the initial offset indicating which side of the boom ( perpendicular to the boom) the first push came from. Wouldn't the earths magnetic field influence a coil/magnet assembly type sensor? You mentioned shielding in the coil/magnet type, This could work for a Hall sensor also. Other question: Why isn't the coil/magnet assembly on a Lehman mounted on the end of the boom where most of the offset/movement takes place? Jim Cristiano weitech@.......... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: mgray1@................ (Mike Gray) Subject: Re: Stratifying air in the enclosure Date: Fri, 25 Oct 1996 18:34:01 -0500 Bear with me as to a different take on this issue. Concrete and other dense materials, including rock, of course, have what is called thermal lag. This allows a basement to stay at relatively the same temperature year round. In the summer the ground is soaking up heat. In the winter it releases it to the basement via the basement walls. In the fall and spring, with what is often wide temperature variations over the course of a day (even hours), the lag can go in both directions until there is a constant trend one way or the other. In a confined environment such as the seismic sensors', a fluctuating lag results in changes sufficient to cause disturbances in baseline noise levels, etc. You don't notice a constant trend so much because it occurs over a much longer period and is slower to change on top of that. Add to this the direct effect of the sun's heat, especially on what is a normally shaded (in the summer) or non-shaded (in the winter) sensor due to the sun angle, and you have even more fluctuation. Mike Gray MO Bureau of Emergency Medical Services (Dept of Health) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ct@....... (Charlie & Terri Thompson -- Buda MicroRanch ) Subject: Closing in on the thermal noise problem Date: Fri, 25 Oct 1996 20:50:48 -0500 Mike Gray writes: >Bear with me as to a different take on this issue. Concrete and other dense >materials, including rock, of course, have what is called thermal lag. This >allows a basement to stay at relatively the same temperature year round. In >the summer the ground is soaking up heat. In the winter it releases it to >the basement via the basement walls. > I think Mike is correct. The change can be ABRUPT from one day to the next. As soon as the AIR TEMP falls below the CONCRETE TEMP convection currents will cause the warm air at the bottom of the box to move upwards...then cool off and drift downwards...a constant perpetual motion machine. The fix is simple. Make sure the slab-warmed air is always the COOLEST air in the box by putting a heater at the top. Heavy air on bottom (cool) and lighter warm air always on top will allow stratification occur stopping the convection cycle. Tonight the Texas air has become warmer than the slab and the sensor is again quiet. I'm going to set up my indoor/outdoor thermometer such that the outdoor sensor probe is taped to the concrete slab. I can then switch the electronic thermometer between outdoors (slab temp) and indoors (air temp). [Radio Shack has a nifty LCD readout indoor/outdoor thermometer on sale for $9.95.] A noisy Lehaman sensor should correlate to a slab temp GREATER than the air temp thus causing upward convection currents. Now I have to wait for the next cold front to test this theory! -Charlie ct@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Al Allworth Subject: Re: HALL EFFECT Date: Fri, 25 Oct 1996 20:02:24 -0700 > Al, > I'm talking about a Lehman type, horizontal swinging mass without > dampening and a microscopic return to zero. Correct me if I'm wrong, > but isn't the idea of suspending an inertial mass on a hinge to > decouple it from the earth and to provide a zero point from where > measurements of earth movements are taken? The inertial mass of the > weight stays in one place as the earth move back and forth. If a > movement of 1mm/sec came through, the generated signal would be > an offset displacement signal in real time with the initial offset > indicating which side of the boom ( perpendicular to the boom) > the first push came from. You have described exactly what is happening and how we use the instruments. In reality, though, we are measuring acceleration. In other words, even though the weighted horizontal pendulum stands still and the mounting post moves, it is the rate of movement that produces the signal. A short sharp displacement will produce a greater signal amplitude than a slow displacement of greater distance. This is the same principle that causes a bicycle generator to produce a greater voltage if you pedal faster. A true displacement transducer will produce a continuous signal showing its position. If it is a voltage output device there will be a continuous voltage output when displaced. With the horizontal pendulum if you displace the base quickly 1/2 inch the weight will eventually move over 1/2 inch as well and in the process will generate a voltage oposite but much less than what it generated when moved quickly. It will also probably overshoot and settle out in an oscillatory pattern. If the pendulum is critically damped the overshoot will be minimal but damping slows the initial swing and lowers the output. If displacement indication is needed it can calculated from the acceleration data but I don't remember the equation at the moment. The process is integration. I hope this helps understanding what I was getting at. > Wouldn't the earths magnetic field influence a coil/magnet assembly > type sensor? You mentioned shielding in the coil/magnet type, This > could work for a Hall sensor also. The type of shielding needed on the Lehman coil is electrostatic, and can be accomplished with aluminum foil. The foil must not form a shorted turn around the coil or the output will be effectively shorted out even though the foil is insulated from the wire. The foil must be wrapped through the coil just as you would tape the coil to keep all the wires in place. When you get completely around and are about to wrap the foil strip over the place where you started insulate the part where you started and then complete the shield by continueing to wrap over the foil covered by insulating tape, not allowing the finishing layer to touch the beginning layer. The foil should be connected to the shield if you are using coax cable. I use shielded twisted pair and connect the foil to the shield and the coil to the twisted pair. The shield for a Hall device must be of magnetic material such as Mumetal or some of the more recent exotic alloys. Hall devices should not need electrostatic shields as described above. > Other question: Why isn't the coil/magnet assembly on a Lehman > mounted on the end of the boom where most of the offset/movement > takes place? There are many variations of the horizontal (nearly, would not have a recentering action if not tilted slightly) pendulum. Mechanical construction and designers choices often play as large a part as the physics of the device. If you built it that way it would probably work as well but it probably should not be called a Lehman. > Jim Cristiano weitech@.......... *************************** Al Allworth, Pasadena, CA aallworth@........ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lyzenga@................. (Greg Lyzenga) Subject: Re: Macintosh software Date: Mon, 28 Oct 1996 14:26:50 -0700 >Does anyone know about Macintosh software that would work? I could, I >suppose get another computer, but I'd rather not. Todd: I have a Macintosh-based Lehman seismometer system. It's all home-grown, and as yet I have not got around to writing the software necessary to make it "Winquake-compatible". However it's just a matter of my devoting the time to the task, so if I get some encouragement, I'll be more likely get on it. If you'd like to find out more about my system, feel free to get in touch with me and I'll try to help you out. - Greg P.S. Theoretically, I suppose another option might be to use some kind of an emulation scheme with SoftWindows, but I don't have any experience in that direction. |Gregory A. Lyzenga *** (909) 621-8378 |Dept. of Physics, Harvey Mudd College *** fax (909) 621-8887 |Claremont, CA 91711-5990 |http://www.physics.hmc.edu/profs/lyzenga.html _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: bob@................. (Bob Hammond (USGS-AVO Geophysicist)) Subject: Re: Status at Rainier Date: Mon, 28 Oct 1996 16:39:00 -0900 From: watson@................ (Charles Watson) Subject: Re: Macintosh software Date: Mon, 28 Oct 1996 19:00:24 -0800 Greg Lyzenga wrote: > > >Does anyone know about Macintosh software that would work? I could, I > >suppose get another computer, but I'd rather not. > > Todd: > I have a Macintosh-based Lehman seismometer system. It's all > home-grown, and as yet I have not got around to writing the software > necessary to make it "Winquake-compatible". However it's just a matter of > my devoting the time to the task, so if I get some encouragement, I'll be > more likely get on it. If you'd like to find out more about my system, > feel free to get in touch with me and I'll try to help you out. > Greg, I would be interested in a Mac-based seismometer system. I have been lurking in the background to this group for a couple years, listening to the "Winquake" stuff, thinking "oh, gosh, one of these days, I've got to blow the dust off the ol' PC and get on with this monitoring thing..." But, I'd rather use the half dozen Macs that I regularly use to process Seismo-Watch material anyway. There so much easier to use, ya know. They even come with a trash can... :-) Just loaded the upgrade to System 7.5.5 over the weekend and, whee, it made my PowerBook 5300cs really scoot! So if you need more words of encouragement, I would be glad nudge you. --- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Reduce convection near seismometers Date: 29 Oct 96 10:44:01 EST Hi, There has been a lot of traffic about the source of noise with Lehman and other seismometers. I think that there is general agreement that air currents can be a source of noise (but obviously not the only source). I can offer a little quantitative data which may help thinking about this. My Lehman sits on the concrete floor of my basement. I built a box of 2" thick styrafoam. This material is available from lumber yards. Styrafoam this thick is nearly a perfect insulator under the conditions discussed. The pre-amp is outside the box. The box is 16" wide by 39" long by 24" high (inside dimensions) and has a lid of the 2" stuff which just sits on the top. The gap between the lid and the box nowhere exceeds 1/8". The 4 sides of the box were glued together with Elmer's white glue. The box is taller than necessary but this required less cutting and probably does no harm. A resistor is attached to the center of the lid and spaced about 1" from the lid. The 5 ohm resistor is supplied with 9V AC from a flea market transformer. This dissapates 16 watts. Using a thermistor and an ohmmeter, I measured the temperatures shown in the following table: Location inches from floor deg F Room air 36 65 Floor outside box 0 63.0 Inside box 24 (top) 78.6 " 18 76.5 " 12 74.5 " 6 72.4 The temperatures inside the box are quite constant over a period of a few minutes but variations are seen in the room temp. over this sort of time. The floor temp. was measured by placing the thermistor beneath a square of styrafoam pressed against the floor. Observations:1. The rather small heater power (16 watts) raises the temperature in the box quite a bit. 2. There is a considerable temperature gradient in the box with the top hotter than the bottom. My intuition (unsupported by any evidence) sez that this temp. gradient is plenty to stagnate the air in the box and prevent convection since the longitudinal temp. gradient should be small given the good insulation. ---- The books say that a major cause of the seismic background (microseisms) is ocean waves breaking on the shore. I had a brief discussion with Paul Richards of Lamont obs. and he says that the only way to reduce this problem is to locate away from any ocean. They have the use of a Russian site in the middle of Siberia which is the farthest from an ocean of any place on earth. This suggests that I should move back to my home town, Wichita, but it probably won't happen. When the nor-easter of 10/19 went up the east coast and dumped 7.23" of rain on me, my noise level was high. I hope to try to correlate my noise level with wave height on the Jersey shore more quantitatively . If someone could suggest an internet source of daily wave height data, I would appreciate it. I have a vague impression that ocean storms are more frequent during the change of seasons, e.g., fall to winter. This may account for some to the reports of higher noise at these times. Bob Barns Berk. Hts., NJ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lyzenga@................. (Greg Lyzenga) Subject: Lehmans and thermal noise, etc. Date: Tue, 29 Oct 1996 08:40:31 -0800 Well, it is with a mixture of satisfaction and some embarrassment that I report, thanks to all the good discussion on this list, the problem I said had stumped me for years is solved. After some experiments over the weekend, I am convinced now that it *is* indeed due to air convection when the air temperature drops below the concrete slab's temperature. The reason I feel sort of sheepish about this is that the idea had occurred to me a long time ago, only I had it backwards! I figured at the time that maybe the concrete needed to be heated, so I got an electric blanket and put it on the bottom of the enclosure. The problem only got worse (duh!). Now if I'd only stopped to think for two seconds about it, I'd have realized I wanted the warm air on *top* for stable stratification! Wow, and to think I call myself a physicist! This is much more embarrassing than always forgetting where you put your glasses... 8-) Anyway, installing a couple of light bulbs in the *top* of the box immediately and dramatically improves the thermal noise situation for me, although the bulbs do introduce a certain amount of their own turbulence. Now that I seem to have a handle on the problem, I think the next step will be to experiment with some of the styrofoam insulation ideas that you all have been discussing and really put this to rest. Thanks to everybody for the great ideas! - Greg |Gregory A. Lyzenga *** (909) 621-8378 |Dept. of Physics, Harvey Mudd College *** fax (909) 621-8887 |Claremont, CA 91711-5990 |http://www.physics.hmc.edu/profs/lyzenga.html _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: mgray1@................ (Mike Gray) Subject: Re: Reduce convection near seismometers Date: Tue, 29 Oct 1996 12:02:28 -0600 >Hi, > There has been a lot of traffic about the source of noise with Lehman and >other seismometers. I think that there is general agreement that air currents >can be a source of noise (but obviously not the only source). I can offer a >little quantitative data which may help thinking about this. > ............ >Bob Barns >Berk. Hts., NJ > Thanks, Bob for some interesting data. In regard to my previous posting about thermal lag, certainly thermal breaks reduce that effect. Could you elaborate on how you got a good base connection with your thermal break? Perhaps that small connection is not enough to cause a problem. The thermal break over the rest of the floor area in addition to the heat source is apparently enough to temper the environment. I agree that ocean waves breaking on shore and reefs can contribute to the noise but I always thought that they were much more pronounced at high tides and/or certain lunar phases. I may have been thinking that most of what has been discussed here referred to more constant increased noise, even during low tides. My first impression is that the rainy seasons (spring and fall) would affect the ocean wave situation, as you indicate. My second impression is that if we are dealing primarily with ocean waves, tides/lunar phases should provide the proof of that. Anybody care to look at a possible correlation? Mike Gray MO Bureau of Emergency Medical Services (Dept of Health) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Dan Dzurisin Subject: Status of Mount Rainier Date: Tue, 29 Oct 1996 09:33:52 -0800 There is no truth to the story being circulated by some radio and television stations in the Pacific Northwest, as reported on the Public Seismic Network email list server, that Mount Rainier is at orange alert. In fact, activity at the volcano is at a normal, background level. The root of the erroneous reports may be the fact that this month marks the tenth anniversary of the last dome-building eruption at Mount St. Helens. This was reported by Oregon Public Broadcasting yesterday in a story that also mentioned that scientists now regard Mount Rainier as the most dangerous volcano in the Cascades. The U.S. Geological Survey has documented the hazards posed by long-travelled debris flows at Mount Rainier, and the USGS and University of Washington monitor seismic activity at Mount Rainier continuously. Future eruptions or debris flows at Mount Rainier may threaten communities in the area, but for now the volcano remains quiet. ====================================================================== Dan Dzurisin U.S. Geological Survey dzurisin@.................. Volcano Observatory 360-696-7826 (office) 5400 MacArthur Blvd. 360-696-7610 (fax) Vancouver, Washington 98661 ====================================================================== _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: JAMES CRISTIANO Subject: QuakeAlert Date: Tue, 29 Oct 1996 13:06:10 -0800 Dr. John Lahr, re: QuakeAlert Thanks for your response. I just got a copy of your e mail today. Seems that the boss thought it was junk mail. I find it hard to believe that it can distinguish between seismic and other generated vibrations. On the other hand, I remember watching a show on earthquakes a while back and it showed a segment on a city in Japan where they installed "P" wave detectors that were up-linked to an early warning system. I can't remember the name of the city. Anyone remember the show or know who to get in touch with in Japan who might have information on this? I think the system was in a test phase. Might be interesting to find out if it would work or not. Jim Cristiano weitech@.......... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) Subject: Re: QuakeAlert Date: Tue, 29 Oct 1996 14:07:26 -0900 Jim, The only "early warning" system that I am aware of involves rapidly locating an earthquake with the P phases from stations near the epicenter and then broadcasting an alert to more distant locations. Depending on the speed of the location process and the distance of the "more distant" location, there can be a warning a few seconds prior to the arrival of the S phase. This system was implemented on a temporary basis to warn workers at Oakland highway collapse of aftershocks from the Loma Prieta earthquake. JCLahr _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ct@....... (Charlie & Terri Thompson -- Buda MicroRanch ) Subject: Re: Lehmans and thermal noise, etc. Date: Tue, 29 Oct 1996 21:51:44 -0600 Well I've been waiting on the Texas weather to verify the thermal noise theory and apply the heater solution. Tonight when the sun went down the air temp finally dipped below the slab temp: 70 degrees for the slab and 67.9 degrees for the air. I have a nice 3 hour WinQuake plot of the noise level rising. After this posting I will turn on the light bulb and record the noise (hopefully) going down. I'll be happy to share the expected plots with everyone. Thanks to all who shared their thoughts on this....I learned something! -Charlie Thompson Buda, Texas ct@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert Avakian Subject: Re: EARTHQUAKE TIMING Date: Tue, 29 Oct 1996 21:57:14 -0800 RON WW025 wrote: > > DUE TO THE INACCURACY OF THE REAL TIME CLOCK IN THE IBM PC. I HAVE > CONSTRUCTED A HOME MADE CLOCK USING A 10 MHZ CRYSTAL CONTROLLED CLOCK IN > A OVEN THIS IS PHASE LOCKED TO A RUBIDIUM STANDARD AT TWO OF OUR FIVE > TELEVISION STATIONS WHICH USE A RUBIDIUM STANDARD. THE CLOCK HAS A > DIGITAL READ OUT IN THE CONVENTIONAL MANNER BUT ALSO OUTPUTS OF 10 MHZ > DOWN TO 1 HZ. I WISH TO FEED THIS INTO THE COMPUTER TO EITHER CORRECT > THE REAL TIME CLOCK OR NOT USE THE REAL TIME CLOCK AT ALL AND USE A > SOFTWARE CLOCK STILL LOCKED TO MY OWN CLOCK. ANY IDEAS ON HOW TO GO > ABOUT THIS? > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > I just recieved a catalog from Parson's Technologies which includes a progarm to link the computer to any one of several "atomic clocks". That might fit your needs and costs a princely $19. It could obviate the need for a separate clock. Avakian Midland Texas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: mgray1@................ (Mike Gray) Subject: Re: QuakeAlert Date: Wed, 30 Oct 1996 09:21:07 -0600 >The correct URL is http://www.gsi-mc.go.jp/YOCHIREN/ccephome.e.html >Larry > >At 11:22 AM 10/30/96 +1200, you wrote: > >>>Jim, try the email address at the bottom of >>>http://www.gsi-mc.go.ip/YOCHIREN/ccephone.e.html >>>The link works. >>> >> THE Link Didn't Work........ not to worry Dave N. Was too late in a hectic day to read my printing when I was seeing double and cross-eyed at that! At least I got everything right except for one letter. Mike Gray MO Bureau of Emergency Medical Services (Dept of Health) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Re: Reduce convection near seismometers Date: 30 Oct 96 10:24:30 EST Mike Gray, I don't understand your terms "thermal break" and "base connection". Upon further reflection, I'll bet that the whole subject of microseims has been studied to a fare-thee-well and there must be dozens of papers in the seismological literature. What we need is for someone familiar with this literature to point us at a good review article. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Mike Stickney Subject: microseisms Date: Wed, 30 Oct 96 09:15:17 MST I have been lurking in the background for several weeks and have followed your discussions with interest. Perhaps I can offer a little information about microseisms. As the operator of a regional seismograph network in western Montana, I have recorded thousands of hours of microseisms. They are always present at some level but periodically, their amplitude increases dramatically. These periods of increased microseism amplitude typically last from 12-36 hours and almost always occur from October through April. I was told in school (and believe) that these episodes of increased microseism amplitude correspond to low pressure weather systems moving onto the Pacific coast, although I have never taken the time to make a careful study of the correlation. There have been published studies of microseisms. A quick search of the Cumulative Index of the Bulletin of the Seismological Society of America lists a paper by Webb and Constable (1986, Microseism propagation between two sites on the deep seafloor; v. 76, pp.1433-1445) as the most recent BSSA publication that may answer some of the questions raised in the discussion group. In this paper, the statement "The peak near 0.08 Hz is caused by seismic waves forced by the steepening and breaking of surface gravity waves (swell) along the coast" is attributed to Hasselmann (1963, A statistical analysis of the generation of microseisms; Rev. Geophys. Space Phys., v. 1, p.177-210). The article goes on to say that "This is a "primary" frequency peak because the seismic waves are predominately at frequencies near the primary swell frequency." -Mike Stickney Montana Bureau of Mines and Geology _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Re: QuakeAlert Date: Wed, 30 Oct 1996 08:32:40 -0800 Please be aware of the Guerreo Project along the central Mexican coast which has successfully warned Mexico City of very large earthquakes along the central American subduction zone from 30 -90 seconds prior to S-wave arrival. When a potentially damaging quake occurs along the Guerrero segment, the coastal accelerograph network trips, implimenting a warning systems in Mexico City which alerts the people of the impending shaking. The large distance proves an advantage for these types of distant early warning arrays. Once the distance early warning system is perfected, similar arrays could be deployed for other regions of the world as well. I strongly believe any warning is an advantage to saving lives and several creative systems could be designed around this concept to impliment life-saving devices (ie; waring lights on bridge or overpass approaches, sirens in areas of high liquefaction risk, automatic shut-off of critical pipeline utilities, etc). Sounds like a nitch market to capitalize on, eh? --- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ct@....... (Charlie Thompson) Subject: Convection Currents in Lehman sensor housing Date: Wed, 30 Oct 1996 11:57:25 -0600 Using a nifty digital timer I set up my box heater to come ON at exactly 5:00 am this morning... as predicted I have a nice SDR record of the noise going DOWN fairly quickly starting at 5:00 am. It only took about 5 minutes for the noise to drop and level off. ....more observations and expriments to follow. -Charlie Thompson Buda, Texas PS. My guess is that insulating the BOTTOM of the housing might obviate the need for a heater. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ct@....... (Charlie Thompson) Subject: Seismic warning and gas shutoff systems Date: Wed, 30 Oct 1996 12:04:09 -0600 > >Once the distance early warning system is perfected, similar arrays could be >deployed for other regions of the world as well. I strongly believe any warning >is an advantage to saving lives and several creative systems could be designed >around this concept to impliment life-saving devices (ie; waring lights on >bridge or overpass approaches, sirens in areas of high liquefaction risk, >automatic shut-off of critical pipeline utilities, etc). > >Sounds like a nitch market to capitalize on, eh? If you do a US Patent search on keyword "seismic" you will find that there are a couple of patents by individuals pertaining to automatic shutoff of gas/utilites during a seismic events. I think the individual inventors were in SF and LA areas of California. The CNIDR patent search engine on the Web is a great way to find related seismic stuff. -Charlie Thompson Buda, Texas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Re: microseisms Date: Wed, 30 Oct 1996 09:20:05 -0800 Seismo-Watch is geared to report activity from the established monitoring networks in the United States and the world. The former Seismo-Watch Newsletter tracked the weekly activity from these networks and displayed it in a high quality graphic format with bullet text descriptions During the early Spring of 1996, two pulse of increased microseismic activity affected nearly every network in North America. Coined "The Spring Push", it began with a significant increase in activity in Southern California during the first two weeks of April. In subsequent weeks, other networks reported elevated activity. Even the Southeastern Canadian network reported an increase in activity during late April and early May. The only region that did not report elevated seismic activity was the New Madrid-SE networks. Has anyone else tracked similar continental seismic pulses? Charlie --- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Re: Seismic warning and gas shutoff systems Date: Wed, 30 Oct 1996 09:30:11 -0800 Charlie Thompson wrote: > > > If you do a US Patent search on keyword "seismic" you will find > that there are a couple of patents by individuals pertaining to > automatic shutoff of gas/utilites during a seismic events. But what about the large picture of regional warning arrays and warning devices? John Larr's recall of the rescue workers on the Embarcadero Freeway is a great example how these systems could be employed. Imagin a 7+ earthquake along the Point Rayes segment of the San Andreas. It would take several 10s of seconds for the seismic waves to reach the high liquefaction risk regions around the South Bay. Deployment of early warning systems could be designed to facilitate life saving procedures there. Charlie --- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Seismic warning and gas shutoff systems Date: Wed, 30 Oct 1996 13:43:42 -0700 Charles Watson wrote: > But what about the large picture of regional warning arrays and warning > devices? John Larr's recall of the rescue workers on the Embarcadero Freeway > is a great example how these systems could be employed. > > Imagin a 7+ earthquake along the Point Rayes segment of the San Andreas. It > would take several 10s of seconds for the seismic waves to reach the high > liquefaction risk regions around the South Bay. Deployment of early warning > systems could be designed to facilitate life saving procedures there. Except that if the last +7 M earthquake had been 20 years before, one might not know what the alarm was all about and it would take some time, several seconds at least, to get one's act together. -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: JAMES CRISTIANO Subject: Hall Effect, again Date: Wed, 30 Oct 1996 12:47:18 -0800 To Al and all, I just got a sample of Allegros high sensitivity Hall effect sensor UGN3507L-U. Its sensitivity is .0025V/Gauss. With the magnet setup described before, I get a .021V/mil signal (8.44 X .0025V = .021V). With a X100 amplifier its 2.1V/mil. Thats 2.1V for each .001" of boom movement! Sounds like a lot to me. With a capacitor the displacement/time signal can be changed to acceleration/time. The Earths magnetic field has a minimal effect on the Hall sensor. Just so I can compare apples to apples, can anyone tell me what the sensitivity of thier coil/magnet setup is? In Volts @ 1mm @ say 5Hz? Before I start winding 1000' of #36AWG wire on a bobbin, I want to make sure I'm not passing anything up. Thanks, Jim Cristiano weitech@.......... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: mgray1@................ (Mike Gray) Subject: Re: Seismic warning and gas shutoff systems Date: Wed, 30 Oct 1996 16:01:03 -0600 >If you do a US Patent search on keyword "seismic" you will find >that there are a couple of patents by individuals pertaining to >automatic shutoff of gas/utilites during a seismic events. I think >the individual inventors were in SF and LA areas of California. >The CNIDR patent search engine on the Web is a great way to find >related seismic stuff. > >-Charlie Thompson >Buda, Texas > Charlie, do you have a specific URL or URL's for patent searches? Is there any cost for use? Mike Gray MO Bureau of Emergency Medical Services (Dept of Health) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: bob@................. (Bob Hammond (USGS-AVO Geophysicist)) Subject: Re: Seismic warning and gas shutoff systems Date: Wed, 30 Oct 1996 11:59:28 -0900 I maintain (and others do as well) that preparedness is the best way to go for quake hazard mitigation. I agree with Ed Cranswick that our collective memory will fail us with an alarm system that is only triggered once every 5 or 10 years. I'd rather be ready ALL the time than have 10-90 seconds to get ready. The gas shutoff device should be mandatory in high-risk areas. I cannot see alerting a whole city to the fact that a quake is coming in less than a minute. I think you'd have more deaths due to panic. that's my 2 cents! Bob. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ct@....... (Charlie Thompson) Subject: Patent database URL Date: Wed, 30 Oct 1996 16:16:26 -0600 For those interested in US Patents the FREE searchable database is: http://patents.cnidr.org/patbib_index.html To download patents for $3.00 each (very good image quality) you can access: http://www.micropat.com/ You'll need to download their viewer and they take a $50 deposit via credit card. (don't send your cc# via email ..phone them with it instead to be secure). I've had good luck with Micropatent they are decent people. Regards, Charlie Thompson Buda, TX ct@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: speaking of micro seisms Date: Thu, 31 Oct 1996 09:18:17 +1200 I live only 3 km from the coast and last nite observed a classic case of watching a cold weather front arrive from the south onto my east coast of the South Is., NZ. The background noise initially in the mid evening was very quiet and the pen trace was almost " Flat Lining" ~ 2300 hrs loc. the noise began to slowly build as the heavy seas began arriving.... some 2-3 hours before the cloud and rain arrived overhead. The seismic noise consisted of ~ +_ 3-4 mm amplitude and ~ 2 sec period. the seismometer I am using is ' Marks Products' L15 BH 4-5 Hz horizontal Geophone... they are very small... 3 cm diam. and 4 cm long. it is potted in a 5cm dia piece of plastic pipe, buried in the ground and coax cable running some 30 metres back into the house to the recorder. Only just shifted to seismom. to the greater distance as I have finally had enough of the man-made noise coming from the neighbour's house.... the hi freq vibrations from their washing machine in spin mode and the clothes drier caused havoc. I've been following the thermal noise prob. with interest as when I fire up the commercial L.P. seismom. I suspect that I will strike similar hassles. thanks for all the input Cheers all Dave Dave A. Nelson Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm ( world wide access ) http:/www.es.co.nz/~dann/home.html ( New Zealand access only ) When All Else Fails...... READ THE INSTRUCTIONS A SMITH and WESSON Beats Four Aces _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: mgray1@................ (Mike Gray) Subject: Re: Reduce convection near seismometers Date: Wed, 30 Oct 1996 15:07:42 -0600 >Mike Gray, > I don't understand your terms "thermal break" and "base connection". > Upon further reflection, I'll bet that the whole subject of microseims has >been studied to a fare-thee-well and there must be dozens of papers in the >seismological literature. What we need is for someone familiar with this >literature to point us at a good review article. >Bob Barns > A thermal break is a method of stopping the flow of heat from something warmer to something colder. The method generally involves using an insulating material. In its most common forms, thermal breaks are used on window and door installations and insulated basements. An additional benefit is the reduction of air infiltration to areas one does not want it in. Caulking is not a very good thermal break, but it is a good way to reduce air infiltration. My reference to the "base connection" was referring to however the seismic sensor is attached to the concrete or rock slab. If those connection points are small in size, I wouldn't see a need for a thermal break at the points. This is because the slab's thermal lag (release of stored latent heat to a colder area, usually the air above a horizontal surface) surface is greater than the mounting point(s). That greater surface area has more of an effect than possibly even the sum of the mounting points. If one were to compensate for the effect of thermal lag by using heaters to make the ambient temperature more stable, there probably isn't any need for a thermal break. A thermal break, if done properly, would eliminate the need for the heaters. Heaters, from what I'm hearing on this list, seem to more than make up for the thermal lag effects. Without knowing precisely how the Lehman or other sensors are mounted, I would say a thermal break is best installed between the areas of most concern (the sensor and what's below it). If the thermal break is below the slab, it would seem that the slab "connection" to the earth would not be as "stiff" as it needs to be. (Excuse my low tech descriptions - I may be trying too hard to simplify.) I don't have a sensor (yet!). But if were to have one and wanted to try a thermal break, I would start with ceiling insulation, foam insulation, or even layers of newspaper if rodents, bugs, and/or moisture are not a problem. The insulating material would be placed directly on the slab and go to the edges of the box cover. I would probably use as much as I could stuff in there without affecting mechanical movements. By the way, I've seen many seismic sensors buried in the ground, which stays at a relatively constant temperature (thermal lag imakes the ground temperature opposite to what the season and atmospheric temperature is). Thus sensor the is not as affected by thermal problems. Since I don't think any of this discussion has appeared in seismology, the best place to steer everyone desiring more info is to building contruction folks or window and door manufacturers. My offering is in the low tech, low cost vein. There may be other, more complex and costly solutions. Mike Gray MO Bureau of Emergency Medical Services (Dept of Health) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) Subject: Re: Hall Effect, again Date: Wed, 30 Oct 1996 13:24:20 -0900 Jim Cristiano writes "Can anyone tell me what the sensitivity of thier coil/magnet setup is?" For comparison, the L4C geophone has a velocity sensitivity (motor constant) of .17 volts per mm/s If you're interested in the output for a given amplitude and frequency, first convert to velocity and then apply the scaling factor above. If the amplitude (A) of the moving coil within the geophone is 1 mm zero to peak @ f=5Hz, then A = sin(2 pi f t) mm Then the velocity, V, of the coil is: V = 2 pi f cos(2 pi f t) V = 31.4 cos(2 pi f t) mm/s The output of the geophone would be: ..17*31.4 = 5.34 volts zero to peak JCLahr ################################# John C. Lahr ################################ U.S. Geological Survey ############################### c/o Geophysical Institute ############################## 903 Koyukuk Drive ########################################################### ########################################################### P.O. Box 757320 ################################ Fairbanks, AK 99775 ################################# Phone: (907) 474-7997 ################################## Fax: (907) 474-5618 ################################### lahr@........ #################################### _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Marks Products seismometers Date: Thu, 31 Oct 1996 14:23:43 +1200 Specifically to Jim Forbes also to those others interested, Jim, the 3 Marks Products seismometers (2 x Horiz. and 1 x Vert.) I have were purchased second hand from the Seismological Obs. here in New Zealand. I was offered them when a seismologist have finished his studys and had no more need for them. The 3 cost me NZ$200.00 apparently they are approx US$75.00 new each. here is the blurp from Marks :: (quote) MARK's L-15 subminiature, digital grade, dual coil geophone has the HIGHEST OUTPUT per unit weight of OF ANY COMPARABLY PRICED GEOPHONE. It has an improved coil-magnet structure which makes this high OUTPUT feature CONSISTANT FROM GEOPHONE TO GEOPHONE, an absolute factor of efficient multiple geophone usage. The L - 15 is housed in a Super - Tuf case assuring the user of a FIELD PROVEN CABLE ANCHOR AND CASE SEAL. MARSH cases are also available for SHALLOW WATER applications. L - 15B Standard freq. range, Hz 4.5-10 Hz Freq toler. + - 0.5 Hz Standard coil resistance, Ohms 150/240/380 Resistance Toler. 5 5 5 Max. Distortion @ 0.7 in/sec @ 12 Hz or Resonance 0.2 % Transconduction Const. V/in/sec + - 10% 0.047 x sqr root Rc Open cct Damp, + - 10% 1.253 / f Coil cct Damp., 11.84 Rc / f(Rc + Rs) Suspended mass, Grams 23.00 Power Sens., mW/in/sec 2.21 Case-to-coil Motion, in p - p 0.080 Basic Unit Height, inches 1.4 Basic Unit diam., inches 1.25 Basic Unit Weight, oz 5.0 MARK PRODUCTS, U.S. INC. Area 713/498-0600 10507 Kinghurst Dr. Houston, Texas 77099 (end quote) address is as of ~ 5 years ago as in their spec sheets PS additional to my earlier comments I have approx a 2 kg cylindrical mass of lead sticking out of the bottom end of the section of pipe that the unit is potted in to give the system sensitivity for recording distant events. am able to record M3.5's up to 300 km 4.5's " 600 km 5.5's " 1000 km although not really designed for L.P. recording it has detected > 6.5 events all around the western South Pacific Hope that is of interest to some Cheers Dave Dave A. Nelson Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm ( world wide access ) http:/www.es.co.nz/~dann/home.html ( New Zealand access only ) When All Else Fails...... READ THE INSTRUCTIONS A SMITH and WESSON Beats Four Aces _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: bfryer@............ (Bob Fryer) Subject: Re: QuakeAlert Date: Wed, 30 Oct 1996 19:08:37 -0800 Hello Mike, As a retired firefighter (35 years service), I'm always trying to stir up people in Emergency Services. Do you know anyone who would care to comment on the content of my WWW page? It will be upgraded in a couple of weeks. Thanks and take care.... Bob Fryer -- Beaverton, OR (Cascadia Subduction Zone) >>The correct URL is http://www.gsi-mc.go.jp/YOCHIREN/ccephome.e.html >>Larry >> >>At 11:22 AM 10/30/96 +1200, you wrote: >> >>>>Jim, try the email address at the bottom of >>>>http://www.gsi-mc.go.ip/YOCHIREN/ccephone.e.html >>>>The link works. >>>> >>> THE Link Didn't Work........ not to worry Dave N. > >Was too late in a hectic day to read my printing when I was seeing double >and cross-eyed at that! At least I got everything right except for one letter. > >Mike Gray >MO Bureau of Emergency Medical Services (Dept of Health) >_____________________________________________________________________ ----- earthquake WARNING research ----- --- http://www.teleport.com/~bfryer --- -- Animals, people, scientific evidence -- _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: New WinQuake Release Version 2.3 Date: Wed, 30 Oct 1996 22:47:26 -0700 Greetings, Some great stuff on the list lately... I just finished a new release of my WinQuake program. The new features are: WinQuake can now process event files greater the 65000 samples. The maximum number of samples WinQuake can handle for all formats (PSN, SAC Binary and PEPP) is now 250,000. Added a dialog box to correct the start time of the event file. This can be used to correct the time of the event file if the system time of the data logging system is off by a known amount. The event display now shows the lock status of SDR at the time the event file was saved. If SDR was locked to WWV (or using the serial port connected to some other reference) you will see a (L) or (?) by the start time display at the top of the screen. The (?) indicates that SDR was locked at sometime but has had no new WWV locks within 24 hours. And as usual, fixed several bug. You can download the new version using the following URL: 16 bit version for MS Windows 3.1 ftp://ftp.seismicnet.com/users/psn/software/wq16v23.zip or http://psn.quake.net/software/wq16v23.zip 32 bit version for MS Win95 and NT: ftp://ftp.seismicnet.com/users/psn/software/wq32v23.zip or http://psn.quake.net/software/wq16v23.zip Please try to use the ftp.seismicnet.com address for downloads. This system is connected to a faster link into the net so downloads should be faster then my system at psn.quake.net. For WinQuake and SDR to read/write PSN format files greater then 65000 samples I had to modify the PSN format a little. For more information on the changes to the PSN format please read the format.txt file at http://psn.quake.net/info/format.txt. Note to SDR users: The next release of SDR (Seismic Data Recorder) will allow the user to save the larger then 65000 sample event files. I should have a new release ready in a few days. Regards, Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Al Allworth Subject: Re: Thermal Effects on the Long Period Lehman Date: Wed, 30 Oct 1996 22:48:24 -0800 At 05:45 AM 10/30/96 -0800, you wrote: >Al, where did you pick up your L-4 sensor? I and a friend found some at a surplus sale in Portland, OR last year. No, there aren't any left. We bought all that were left. They had 12 when he first saw them and bought one, not knowing what they were. He knew I had built a seismograph so when I visited in the area he told me about them not thinking they could possibly be of any use. He and I went back to see if any were left. We found them but some had been bought in the 2 weeks since he had been there. Between the two of us , we bought the rest. They are the 1 Hz varity, and I was able to find connectors at a local surplus store. I have one installed with double stick foam tape to my garage floor under the workbench. My electronics got zapped in that big power outage a few months back and I haven't had time to fix it yet. I hope to soon. My friend is now getting more interested in getting his running. It is interesting how the discovery of a major component stirs up the enthusiasm. When I move next year I hope to have enough room to set up an array to try to explore directional effects. Al ____________________________________________________________________________ _____ Al Allworth. Pasadena,CA aallworth@........ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: bfryer@............ (Bob Fryer) Subject: Re: speaking of micro seisms Date: Wed, 30 Oct 1996 23:09:16 -0800 Hi folks, From my _earthquake WARNING research_ bibliography: Bath, Marcus, Introduction to Seismology, New York: John Wiley, 1973. Geology, geophysics, seismology, microseisms. 3.7 (Microseisms) p97: "During World War II, the Americans were able to trace tropical cyclones in the Caribbean Sea and the Pacific Ocean by means of the microseisms which originated from the cyclones." Take care, Bob Fryer ----- earthquake WARNING research ----- --- http://www.teleport.com/~bfryer --- -- Animals, people, scientific evidence -- _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jeff Batten Subject: How are quakes located on a Global Scale? Date: Thu, 31 Oct 1996 13:43:57 -0800 Looking at the Earthquake Information Messages, I notice that P wave arrival times are listed for about 100 stations. Can someone give me some references, that would describe how quakes are located on a global scale using the P-wave arrival times. What software does the USGS use? If us amateurs had the same software could we not locate the quakes ourselves? Jeff Jeff Batten - Research Engineer Caltech Seismo Lab 818-395-6965 Fax-818-564-0715 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Leigh House" Subject: Re: How are quakes located on a Global Scale? Date: Fri, 1 Nov 1996 10:26:23 -0700 To Jeff: I had thought that someone from the U.S. Geological Survey, perhaps Edward Cranswick, would have responded to this by now, but since I haven't seen a response, I'll try to shame one of them by putting my 2 cents in. Yes, certainly you (or anyone else) could locate earthquakes yourselves, given the arrival time information that is in the earthquake information messages that the Nat'l Earthquake Information Center sends out. The procedure for locating earthquakes is fairly straightforward, but the details of computing teleseismic travel times correctly can be a bit complicated. Nevertheless, since the earthquake seismology community has been locating earthquakes for many years, starting with computers that were far less capable than the slowest PC's now available, the computations can be done on basically any PC that anyone has (yes, even the slow, old original IBM PC should work!). I have a teleseismic earthquake location program, but it is fairly old, and since I did not write it, I can not pass out copies of it. I would assume that, since you are at the Seismo Lab at Cal Tech, you could walk down the hall and find a colleague who has a comparable program. You might even be able to get them to agree to making it available to others. I would be happy to assist with adapting it to a PC if necessary, or with putting a test data set together. I may even be able to persuade a colleague here to assist with adapting the program to a Mac, if necessary. If you cannot find a sympathetic colleague at the Seismo Lab, I can help with contacts there or elsewhere to find a program that can be made available via PSN. Regards, Leigh House On Oct 31, 1:43pm, Jeff Batten wrote: > Subject: How are quakes located on a Global Scale? > > > Looking at the Earthquake Information Messages, I notice that P wave > arrival times are listed for about 100 stations. > Can someone give me some references, that would describe how quakes are > located on a global scale using the P-wave arrival times. > What software does the USGS use? > If us amateurs had the same software could we not locate the quakes ourselves? > > Jeff > Jeff Batten - Research Engineer > Caltech Seismo Lab > 818-395-6965 > Fax-818-564-0715 > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L >-- End of excerpt from Jeff Batten -- ------------------ Leigh House MS D-443 Los Alamos National Laboratory Los Alamos, NM 87545 (email: house@......... Tel: 505-667-1912; FAX 505-667-8487) ------------------ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: mgray1@................ (Mike Gray) Subject: Wierd booms Date: Fri, 01 Nov 1996 14:42:31 -0600 Anybody pick up on their sensors the wierd booms (sonic boom- like) being heard and felt around the Florida panhandle? If so, please upload a file of same somewhere (not to the list!!!!) and post an email to this list as to the location and format of the file. Thanks!!! Georgia monitor(s), please make a special effort to look for things out of the ordinary, possibly making changes to try to capture the data. Thanks!!! Mike Gray MO Bureau of Emergency Medical Services (Dept of Health) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jeff Batten Subject: Global Location of epicenters Date: Fri, 01 Nov 1996 14:14:00 -0800 >To Jeff: >I had thought that someone from the U.S. Geological Survey, perhaps >Edward Cranswick, would have responded to this by now, but since I >haven't seen a response, I'll try to shame one of them by putting my 2 >cents in. >Yes, certainly you (or anyone else) could locate earthquakes >yourselves, given the arrival time information that is in the >earthquake information messages that the Nat'l Earthquake Information >Center sends out. The procedure for locating earthquakes is fairly >straightforward, but the details of computing teleseismic travel times >correctly can be a bit complicated. Nevertheless, since the earthquake >seismology community has been locating earthquakes for many years, >starting with computers that were far less capable than the slowest >PC's now available, the computations can be done on basically any PC >that anyone has (yes, even the slow, old original IBM PC should work!). >I have a teleseismic earthquake location program, but it is fairly old, >and since I did not write it, I can not pass out copies of it. I would >.assume that, since you are at the Seismo Lab at Cal Tech, you could >walk down the hall and find a colleague who has a comparable program. Actually I would have to take the elevator up two floors. Working as a mechanical engineer supporting the shock wave lab, I do not directly interface with the scientists working on earthquakes. Since they are very busy most of the time I try not to disturb them. I though someone here on the list might have the answer. I will have to track down a grad student. Most people do not know that bellow the seismo lab at caltech is a gaint light gas gun that can fire projectiles at up to 7 kilometers per second. This allows the equation of state to be determined for many different minerals. >You might even be able to get them to agree to making it available to >others. If I can get a program I will make it available. I belike that the number of amateurs running long period and short period instruments will allow fairly accurate location of global epicenters. All they need is a accurate clock to record the p-wave arrival time. We could all email the p-wave arrival times to a central site that could calculate the location. Jeff Jeff Batten - Research Engineer Caltech Seismo Lab 818-395-6965 Fax-818-564-0715 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: bob@................. (Bob Hammond (USGS-AVO Geophysicist)) Subject: Re: Global Location of epicenters Date: Fri, 1 Nov 1996 14:36:22 -0900 It takes more than this to shame me! :^) Most of the location programs I'm aware of at the USGS are either mainframe programs or PC programs for local and regional locations which don't lend themselves to global locations very nicely. I know global solutions can be done on a PC because one of the guys I worked for at the Alaska Tsunami Warning Center wrote a BASIC program on the original IBM PC to perform earthquake locations. He spent quite a bit of time entering all the data for the J-B travel- time tables. The input to his program was the arrival times of identifiable phases such as P, S, pP, PP, etc. Since we all use Larry's J-B travel-time tables in WinQuake, I don't think it would be too hard to implement something. Heck, we used to use a globe, string, and J-B tables to measure off distances from stations to epicenters when all we got were phase readings over the teletype. I'll see what I can find out. Bob _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: How are quakes located on a Global Scale? Date: Sun, 03 Nov 1996 20:45:34 -0700 > I had thought that someone from the U.S. Geological Survey, perhaps > Edward Cranswick, would have responded to this by now, but since I > haven't seen a response, I'll try to shame one of them by putting my 2 > cents in. Leigh- I couldn't have said it better myself. I am glad that some US government agencies are willing to help the public. Thank you. -Edward -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: How are quakes located on a Global Scale? Date: Sun, 03 Nov 1996 21:07:46 -0700 Jeff Batten wrote: > > Looking at the Earthquake Information Messages, I notice that P wave > arrival times are listed for about 100 stations. > Can someone give me some references, that would describe how quakes are > located on a global scale using the P-wave arrival times. > What software does the USGS use? > If us amateurs had the same software could we not locate the quakes ourselves? > > Jeff > Jeff Batten - Research Engineer > Caltech Seismo Lab > 818-395-6965 > Fax-818-564-0715 > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L Jeff- >I had thought that someone from the U.S. Geological Survey, perhaps >Edward Cranswick, would have responded to this by now, but since I >haven't seen a response, I'll try to shame one of them by putting my 2 >cents in. (Leigh House) I have forwarded your request to the NEIC staff. As noted by Bob Hammand, the location programs we use (my group that chases aftershocks with portable autonomous digital seismographs, PADS, see http://geohazards.cr.usgs.gov/engnseis/chase_eq.html ), when we must locate earthquakes, are for locating local events. Shamed but unbowed, -Edward -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Cristiano Subject: SSS Date: Wed, 06 Nov 1996 08:35:19 -0700 Hi all, OK OK OK, I'll put my Linear Hall Sensor where my boom is. I wrote a proposal to the local high school on installing and maintaining a seismic station as a school project. The location is Sisters, Oregon. We are in the high desert, just East of the Cascade Mountains. We have active faults, subduction zones and volcanoes. Might be inter- esting. The project could be called the Sisters Seismic Station (SSS). Started scraping up the parts for a horizontal swinging boom type. Picked up two 5 pound barbell weights for $3.00 each at the sporting goods store. They already have a hole for mounting. Got a piece of 5/8" Dia. X 36" threaded rod with nuts and washers from the hardware store. For the boom hinge point, I drilled a 1/8" Dia. X 1/2" deep hole in one end of the rod and glued in a 3/4" long piece of nail with the head cut off. The point of the nail will seat into a shallow " V " drilled into the frame cross piece. Neat and easy. I'll keep ya posted on progress. Jim Cristiano cristiano@........... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: [Fwd: Availability of HYPOCENTER] Date: Wed, 06 Nov 1996 13:55:32 -0700 -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". Barry- I saw your article in SRL, "A Computer Program for Locating Earthquakes Both Locally and Globally" (Lienert and Havskov, 1995; Seismological Research Letters, v. 66, no. 5, Sep/Oct 1995, pp. 26-35.), and I thought that it would be a useful program with respect to the request below. Do you have a Web site? Is the program still available via FTP (elepaio.soest.hawaii.edu, anonymous login, ftp/pub/lienert)? -Edward ----------------------------------------------------------------------- Subject: How are quakes located on a Global Scale? Date: Thu, 31 Oct 1996 13:43:57 -0800 From: Jeff Batten Reply-To: PSN-L Mailing List To: PSN-L@............. Looking at the Earthquake Information Messages, I notice that P wave arrival times are listed for about 100 stations. Can someone give me some references, that would describe how quakes are located on a global scale using the P-wave arrival times. What software does the USGS use? If us amateurs had the same software could we not locate the quakes ourselves? Jeff Jeff Batten - Research Engineer Caltech Seismo Lab 818-395-6965 Fax-818-564-0715 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". From: Robert L Barns <75612.2635@..............> Subject: Re: SSS Date: 06 Nov 96 21:27:15 EST Jim, You may already know about this, but if not:The PEPP (Princeton Earth Physics Project) has a bunch of NSF money to set up seismographs in high schools. They have several already running. You can inquire at wanat@................. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: SEED data file reader Date: 06 Nov 96 22:06:43 EST Hi gang, Paul Richards of Lamont-Doehrty tells me that I can get their quake data by FTP from lamont.ldeo.columbia.edu Sure enough, I download a 491k file called 96090.134524.seed (this is day 090 of 1996 at 13:45:24) with no problem. He sez that these require a SEED (Standard Exchange of Earthquake Data) reader program and sugggested ftp from dmc.iris.washington.edu as a source. I don't see anything there which will run on a PC. Can anyone suggest where to find such a reader? Bob Barns Berkeley Hts., NJ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: SEED data file reader Date: Wed, 06 Nov 1996 19:43:41 -0700 Hi, What you really need is a program that can convert the waveforms in the seed file to SAC binary files. You can then view them with WinQuake. Unfortunately I don't know of a PC based program to do this. I'm sure there's a UNIX program that can do the conversion. If you have access to a unix system you could convert the file to SAC files and then download then to your PC. I did convert one unix conversion program (I found it the DMC Iris site) called csstosac. This program converts CSS waveform files into SAC binary ones. I ported it over to a 32 bit command line program for WIN95 or NT. Because of the long file names used by unix systems it would not work very well with the old 8.3 format. Event files in this format can be found at the International Data Center (http://www.cdidc.org:65120/). They deal with the comprehensive test ban treaty. Some of the EQ events have waveforms. If anyone would like a copy of my version of csstosac drop me a line and I will send you a copy. You will also need a copy to TAR.EXE and GUNZIP.EXE to extract the waveforms. If anyone finds some "C" code to work with SEED files please drop me a line. I can try and see if I can port it over to the PC, if it hasn't been done yet. Regards, Larry Cochrane Redwood City, PSN At 10:06 PM 11/6/96 EST, you wrote: >Hi gang, > Paul Richards of Lamont-Doehrty tells me that I can get their quake data by >FTP from lamont.ldeo.columbia.edu > Sure enough, I download a 491k file called 96090.134524.seed (this is day 090 >of 1996 at 13:45:24) with no problem. He sez that these require a SEED >(Standard Exchange of Earthquake Data) reader program and sugggested ftp from >dmc.iris.washington.edu as a source. I don't see anything there which will >run on a PC. > Can anyone suggest where to find such a reader? >Bob Barns >Berkeley Hts., NJ > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: [Fwd: Re: Availability of HYPOCENTER] Date: Thu, 07 Nov 1996 10:57:29 -0700 -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". Edward, Yes, all the necessary software, including FORTRAN sources, a manual, a PC executable (386 or better) are on our elepaio ftp server. You are welcome to download them. >From an internet connected SUN, PC or MAC: 1. ftp elepaio.soest.hawaii.edu 2. login as anonymous 3. give your e-mail address as a password 4. cd ~ftp/pub/lienert 5. lcd the directory in which you want the files (e.g. c:\hypo) 6. mget * Please let me know if you have any difficulty in getting them to run. I strongly recommend Microsoft Powerstation Fortran as the best way to compile it, although it has been successfully compiled on SUN's with small modifications to the subdirectory structure portions. It will not run on the older 16-bit Fortran compilers such as MS Fortran 5.1. I was recently informed by Jens Havskov that the latest version of the ISC global arrival time CD-ROM, which will be released sometime next year, will contain HYPOCENTER. The present software package includes a program (ISCNOR) that will quickly convert travel times from the existing NEIC/ISC CD-ROM (containing all globally recorded arrival times from 1964-87: a goldmine of information!), to HYPOCENTER format, allowing their parent events to be relocated using HYPOCENTER and IASP91 travel times (rather than the JB times used by the ISC). In its present form, HYPOCENTER does allow the user to interactively select events to locate, with on-screen display of residuals, etc. However, it does not have any graphical interface, although I have included a rather basic plot program utilizing the PLOT88 library (which you have to buy). I would like to write a nice Windows version of HYPOCENTER in C/C++, as it is presently very UNIX-like in its organization. I considered a proposal to NSF to do this, but they didn't seem very receptive to the idea, despite all their hoohah about making the results of science available to the general public. I have also had all my time taken up recently constructing and programming Hawaii's first scanning LIDAR. From: Jim Cristiano Subject: Re: SSS Instrument Date: Thu, 07 Nov 1996 11:18:07 -0700 Darrell Collins wrote: > > Hi, > I too have a school project like yours. > Let me know if you need any small machining work done ( like > for bushings for the weight holes to 5/8 rod, etc ). Darrell, Your'e right! I do need bushings to fit the weight with a ~1-1/16" hole onto a 5/8" threaded rod. If I can't find something that will do the job from the hardware store, I'll measure the hole and let you know what size it is for sure so that you could make a couple. Thanks for the offer. Bob Barns, Thanks for the tip on the Princeton PEPP info. I'll submit this along with my proposal. Re: QuakeAlert Just received my sample QuakeAlert from Tectonics, Inc. I'll let you all know what happens. Thanks, Jim Cristiano cristiano@........... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Steve Hammond Subject: Re: Convection Currents in Lehman sensor housing Date: Fri, 8 Nov 1996 02:56:34 -0800 (PST) On Wed, 30 Oct 1996, Charlie Thompson wrote: >>more experiments So Charlie, how goes the experiment? I was wondering why the Lehmans here were no having problems as the temps started to drop and I realize that the two of them are in wood boxes that are not totally air tight so the temp from top to bottom is the same. Did you happen to try some kind of vent that would allow the heat to keep flowing up-up-and-away? The two here are outside in a wooden 4x8 shed next to the side of the house on a cement slab and each has its own wooden 2x2x4 wooden box covering it. The air escapes via small gaps in the plastic windows in the top of the boxes that allow me to see and access to the devices without removing the covers. I also have another general question for all... The first 3/4 inch of rain took place last week in the bay area. As it does each year, the ground tilt put the Lehman to the side stop on both and I had to re-center each. My question is this: anybody that has dry summer and wet winters, did you notice a shift in the natural frequency of a fixed microseismic source? I have the San Jose lightrail at one end of my block and the 85 freeway, yes-- the joys of urban seismology, and the SP train tracks 1.6km the other way, The FFT of the coda made by the lightrail going down the tracks shifted just as it has done each year starting in 1990 from 11Hz to 8Hz. I've talked to Ed Cranswick about this and think that he will agree that it's kind of an intersting thing to look at. I'm looking for other examples in different area of San Francisco/San Jose and the world to see how they might be effected. I've noticed a couple of things that go along with it. (a) a lot of higher frequency short period noise seems to get filtered out after the rain. (B) Coda data of any kind of wheels passing by the location is much more harmonic than it had been late into the dry summer. I think the effects of this might be to actually have two different levels of site response given different times of the year and weather conditions, which could result in different damage patterns in an earthquake. So if you have data around that exhibits what I describe, please let me know. Regards, Steve Hammond PSN BBS San Jose 408-226-0675 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Steve Hammond Subject: PSN BBS San Jose 408-226-0675 is once again on-line Date: Fri, 8 Nov 1996 03:02:12 -0800 (PST) I fixed the bad hard drive and the San Jose BBS is back on line. There is several years of earthquake data stored on it. There is also some free software. Regards, Steve Hammond PSN BBS San Jose, CA 408-226-0675 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: toddm@........... (Todd Miller) Subject: A cry for help Date: Fri, 8 Nov 1996 09:12:24 +0100 I am building my seismograph and the mechanical parts are straightforward. However, I haven't built anything electronic since the seventies when I assembled vacumn tube Heathkits. My power supply and amplifier don't work and my question is how easy is it to fry the IC's specifically op-amp 941's when I solder them? Are you supposed to solder them in fact, or is there a socket kit to use? What do you all recommend? Thanks in advance- Todd Miller _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Steve Hammond Subject: Re: A cry for help Date: Fri, 8 Nov 1996 10:26:49 -0800 (PST) There is a socket kit to plug IC's in to. Is there a Radio Shack store near you? IF there is you want the 8-pin DIP socket. There is also nice perf hoards with holes to align to the pins for mounting. Where are you located? Maybe we can get you some help. Regards, Steve Hammond PSN BBS San Jose 408-226-0675 On Fri, 8 Nov 1996, Todd Miller wrote: > I am building my seismograph and the mechanical parts are straightforward. > However, I haven't built anything electronic since the seventies when I > assembled vacumn tube Heathkits. My power supply and amplifier don't work > and my question is how easy is it to fry the IC's specifically op-amp 941's > when I solder them? Are you supposed to solder them in fact, or is there a > socket kit to use? What do you all recommend? > > Thanks in advance- Todd Miller > > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Ron Westfall Subject: Re: A cry for help Date: Fri, 08 Nov 1996 10:33:53 -0800 Todd Miller wrote: > > and my question is how easy is it to fry the IC's specifically op-amp 941's > when I solder them? Are you supposed to solder them in fact, or is there a > socket kit to use? What do you all recommend? > It is fairly easy to fry most ICs. It is just a matter of how long the heat has been applied to the chip, and how much heat has accumulated in the chip. The secret to soldering ICs is speed. Speed will come with practice. If necessary, wait between pins to allow accumulated heat to disperse. The other trick is to clamp something metallic (not always possible) to the exposed part of the pins on the top side of the board. This will take heat away from the pins and the chip. Another danger of too much heat is that the solder pads on the printed circuit board will eventually lift off the board. Socketing is much better than soldering. There should be a socket for just about any chip on the market. For small quantities, reasonable prices, and good selection, try: Digi-Key http://www.digikey.com/ 1-800-344-4539 (1-800-DIG-IKEY) The advantage of sockets is that a bad chip can be easily replaced. Whether you solder or socket, it is important to deal with electrostatic discharge (ESD)(static electricity). Many modern ICs can be easily destroyed by the static electricity that builds up on your body. They must be grounded until they are connected into a circuit board. The board should be grounded until it is installed and attached to a ground. While some chips will not be damaged, most electronics shops just treat all chips as if they will blow so that proper handling becomes second nature. The proper technique is to keep all chips in an ESD bag (commonly appears to be a dark translucent smoky green colour with a slight metallic reflectivity) until they are needed. Ground yourself using a proper electrostatic wrist strap and do your work on an electrostatic mat. Both the wrist strap and the mat must be grounded to be effective. Make sure you buy a proper wrist strap, rather than cobble something up yourself. They are pretty cheap, work well, and may save your life. They incorporate a 10 Megohm resistor between your wrist and ground to ensure that you are not electrocuted if you inadvertantly come in contact with a power source. Hope this helps, Ron Westfall westfall@...... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: mgray1@................ (Mike Gray) Subject: Re: A cry for help Date: Fri, 08 Nov 1996 15:09:45 -0600 >Todd Miller wrote: >> >> and my question is how easy is it to fry the IC's specifically op-amp 941's >> when I solder them? Are you supposed to solder them in fact, or is there a >> socket kit to use? What do you all recommend? If you used a soldering GUN, as many of us used back in the vacuum tube (valve) days, you probably literally fried the IC's. Even if you use a socket, you should use a small wattage soldering iron. Many members of this list are now groaning "duh!!!" However, from my experiences with dealing with people getting back in the hobby, one can not make basic assumptions. Mike Gray MO Bureau of Emergency Medical Services (Dept of Health) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ct@....... (Charlie Thompson) Subject: Re: Convection Currents in Lehman sensor housing Date: Fri, 08 Nov 1996 17:41:50 -0600 I promised to report on my Lehman convection current problems here goes: The solution for me was actually quite simple (almost!). A small light bulb in the top of the box nails the problem completely! Only one additional small problem: Light escapes from the small cracks in my styrofoam box...flying insects...namely moths...home in on the light during the night. They get inside the box and start bumping the sensor. The result is magnitude 10 moth-induced events. My EVENTS directory has about 20 moth-induced events per night! Now I have to seal ALL cracks to keep the bugs out...not the air! I am optimistic that sealing the box with the bulb inside will bring the job to completion. I have a nice plot of the noise level changing as the bulb is turned on for 1 hour and then off again. Slowly but surely I'm getting there! My advice to all Lehman sensor owners would be USE A HEATER unless you have your sensor indoors in a controlled climate. -Charlie Thompson ct@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Ken Navarre Subject: 12 bit A/D Date: Sat, 9 Nov 1996 07:54:48 -0800 (PST) Saw this on the newsgroups today. Just thought I'd pass it along. Haven't heard of these guys before so... Ken. Newsgroups: sci.geo.earthquakes Subject: $59 12-bit A/D for Seismometer Date: Fri, 08 Nov 1996 22:54:38 -0600 Organization: ADNAV Electronics The seismometer described in the April 1996 Scientific American "Amateur Scientist" column makes a simple and inexpensive instrument with suitable sensitivity for the amateur geophysicist. The article suggested acquiring the seismic signal into a PC for trace plotting and signal analysis. A low-cost A/D that is well suited for the application has been introduced by ADNAV Electronics. The LPT:Analog! v2.0 is a 12-bit Analog-to-Digital adapter for the PC parallel printer port which sells for US $59. Since the LPT:Analog! v2.0 connects directly to the printer port of any PC, installation is extremely simple. This adapter is a very convenient interface for acquiring analog signals directly on a PC at rates of up to 7,500 samples per second. Signal conditioning information is supplied, making it easy to collect data from analog-output instruments (e.g. the ADXL50 accelerometer amplifier/filter in the Scientific American seismograph, sensors, 4-20 mA loops and many other analog signal sources). +-----+ =| |* +-+ +------- | | \ | | \ | | \ BNC Connector | | \ / | | | / | | +-+ | | +-----+ TO PC's | | | | Analog PRINTER <- | | LPT:Analog! | o | <- Signal PORT | | | | Input | | +-----+ | | +-+ | | | | | / | | / | | / | | / \ +-+ +------- \ / =| |* Shielded / +-----+ Hood Male DB25 Power for LPT:Analog! v2.0 is derived directly from the PC's printer port. The micropower design of the adapter's internal circuitry ensures that it can be used with virtually any desktop, laptop or notebook PC on the market. This, in conjunction with its small size (a shielded case measuring 2" x 2.4" x 0.7"), makes LPT:Analog! v2.0 ideal for PC-based data acquisition applications that require ultimate portability and flexibility. LPT:Analog! v2.0 is supplied with software utilities that enable real-time display of acquired waveforms, ASCII-format data logging to disk, as well as high-resolution spectral analysis of acquired data. The source code (QBasic, C and assembly) for these utilities is included at no extra cost. In addition, software drivers, VisualBasic DLLs and programming examples are also provided. For more information, please contact: ADNAV Electronics 58 Chicory Ct. Lake Jackson, TX 77566 (409)292-0988 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: [Fwd: Re: A question regarding the PSN name. (fwd)] Date: Mon, 11 Nov 1996 16:42:35 -0700 -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". Steve Hammond wrote: > > Your welcome and nice work on your end too-- > > I called Mrs. D. and it turns out a guy and his wife are starting a home > business doing T-shirts and caps insignias, and they were going to do a > bunch of HAM stuff and wanted to include some PSN logos. I told D. to > tell them, sure-- but also send them a note that says if anybody makes a > real fuss, we might need to re-think it. I also told her to tell them to > send me a price list kuz I want to get one of each for my Christmas > list... I assume it's OK by you also if they use the PSN name on a cap? I I have no objection --- the more publicity, the better --- but as far as the legality of it all, someone more cognizant than I will have to judge, i.e., I'm from the government, and I'm here to help you, etc. > can't see any reason we might not want to have a blue ball cap with a logo > and PSN in yellow letters on it. I was thinking that I might have "we > recoreded it first" put in small letter on the back of the hat. > > On another seismic note: I see you are published in the Oct BSSA, Urban > Seismology-- Northridge Aftershock ... Nice paper. I'm still reading > it in fact. I just need more weeks in the week to do all I need to do. I think it's a pretty wretched paper with respect to what I originally had in mind. However, as my state of depression continued, and I was unable to write anything, others took up the slack and wrote what they thought was important, and they were probably right with respect to what the "professional" seismology community wanted to see. If I had been more together, I would have addressed some of the issues raised in the following two abstracts of presentations made at the 1994 Annual Meeting of the Seismological Society of America that was held in Pasadena, CA, three months after the 17 January 1994 Northridge Earthquake in California. ------------------------------------------------------------------------ DAMAGE DONE BY THE 1994 NORTHRIDGE, CALIFORNIA, EARTHQUAKE AND THE SPATIAL DENSITY OF SAMPLING STRONG GROUND MOTIONS CRANSWICK, E. U.S. Geological Survey, MS 966, Box 25046, Federal Center, Denver CO 80225, cranswick@................... The mainshock and aftershock sequence of the 17 January 1994 Northridge, California, Earthquake caused more economic loss than any previous natural disaster in U.S. history, and the strong ground motions it produced were monitored by an unprecedented number of instruments (including 75 portable digital seismographs). Aftershock recordings from small-aperture arrays (Frankel et al., this session) indicate that peak ground motions can vary by a factor of two over distances of one city block (200 m) and that this is approximately the maximum distance over which peaks can be reliably correlated in general. Damage was observed to vary by more than a unit of Modified Mercalli Intensity (MMI) from block to block. These observations suggest that the length of a city block is the appropriate inter-station spacing for the unaliased sampling of strong ground motions to determine their correlation with damage. This implies a requirement of approximately 2x104 sample points in the San Fernando Valley alone. Lack of instrumentation forces the strategies of data acquisition to lie between the extremes of either distributing stations uniformly, which undersamples by 2-3 orders of magnitude, or concentrating stations at a few sites of locally intense damage and/or ground motion, which may be unrepresentative of the overall pattern (e.g., Tarzana). The effects of variables of even simple models which formulate damage as a function of source, propagation, 1-D site response, and structural response cannot be resolved without densely sampling ground motions over a wide area. More realistic models of sedimentary-basin response (e.g., Frankel, 1993) demonstrate that ground motion is a non-linear function of the source and the precise 3-D velocity structure of the epicentral region. The relative responses of adjacent sites can vary by a factor of three because of the direction of rupture propagation alone. This implies that the "site/source" response, like the weather, can only be predicted in a probabilistic fashion based on a history of observations. To provide a solid empirical basis for understanding how earthquakes impact the modern urban infra-structure, "state of the market" digital technologies can be used to produce a cost-effective means of recording ground motions with a spatial density comparable to population density. ------------------------------------------------------------------------ THE PUBLIC SEISMIC NETWORK (PSN) OF PASADENA, HAM RADIO AND THE 17 JANUARY 1994 NORTHRIDGE EARTHQUAKE DARBY, D., DARBY, J., PSN, 841 Belvidere St., Pasadena, CA 91104, (818) 797-7509, ddarby@................. BBS (818) 797-0536; HAMMOND, S., PSN, 5847 Falon Way, San Jose, CA 95123, BBS (408) 226-0675 (Sponser: CRANSWICK, E.). [edited by Benjamin Gardner, USGS/PSN volunteer] By word of mouth via HAM radio, the Public Seismic Network has reached hundreds of people. In a crisis like the Northridge Earthquake, citizens need to play an organized role in assistance and communications; this is a motivation behind HAM radio networks. Linked to a PSN, HAM radio is a viable way of educating people about earthquakes and, during a quake, of passing on vital, realtime information. I learned of the PSN through amateur radio and contacted the PSN/San Jose BBS. We had already built a Lehman-type seismometer and had a chart recorder. We started operating a PSN BBS in Pasadena. I began a weekly net on amateur radio, giving out weekly earthquake data from both regional and world-wide events. PSN/Pasadena now has a user base of over 500. We are working on interaction with schools; several science teachers use the BBS. When the Northridge Earthquake struck, my role was to man the radio and take 'felt' reports; my husband handled the chart recorder and measured the P&S waves to calculate distances. My son, also a HAM, handled telephone calls. Within 5 minutes of taking those felt reports, we knew where the epicenter was. Those reporting 'rolling motion' were farther away, and those reporting 'sharp jolts' were closer. From experience of the 1991 Sierra Madre Earthquake, I knew that those at the epicenter would not be reporting in right away; they would be busy taking care of their own, or checking for damage and gas leaks. When those at the epicenter started reporting in, the reports turned to reports of fires and help needed. We became an emergency hotline, logging hundreds of calls within 72 hours. Calls came in asking for damage reports where relatives lived, for help needed in fighting fires, for advice about gas leaks, etc. Even as immediate needs were handled, we hoped to be of longterm use by putting information on the BBS as we got it. It may be still unclear how the seismic data can be used for research and to help us out. But the information helps the people listening. We had news media monitoring that frequency, and we had all the Emergency Operating Centers tuned into it. Police and fire agencies also monitor it. I may never know how many it helped, but we received many grateful responses. ------------------------------------------------------------------------ > Life treating you OK? > > Regards, > -Steve > Meanwhile I am waiting for the English language to become a subset of MicroSoft and for the digital tsunami ("tidal wave") of the World Wide Web to engulf us all. Give my best regards to your family. -Edward -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". From: Edward Cranswick Subject: Re: A question regarding the PSN name. (fwd) Date: Mon, 11 Nov 1996 17:00:11 -0700 I just realized that it would make sense to put the prior email interchange related to this issue on the PSN mailing list. Sorry for the synchopation of communication. > > On Sun, 10 Nov 1996, Edward Cranswick wrote: > > > Steve- > > Thank you for the historical record! > > -Edward _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Lehman period Date: 11 Nov 96 21:12:56 EST Hi gang, The only periods of Lehman seismometers I have heard about are in the 16-18 sec. range. It would be interesting to hear opinions and/or experiences with Lehman's of longer periods. Since I have little hope of catching local events, long period seismometers are of special interest. The only deterrant to longer periods that I have thought of is possible excessive sensitivity to tilt which might make frequent re-centering necessary. Is the mechanical limit to longer period the stiffness of the suspension wire? I find it a little hard to believe that is a factor since the moment arm for bending the wire is very long. However, the centering force is in the milligram range so wire stiffness might be important. Bob Barns Berkeley Hts., NJ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon Subject: Re: Lehman period Date: Mon, 11 Nov 96 20:54:30 -0500 I have wondered about the limiting factors also. A recent post mentions possible problems with atmospheric pressure variations. The tilts certainly will be a problem so I have designed an electronic feedback system that takes out drift due to tilt. My instrument right now has all pivot supports so there is no wire stiffness problem, but there could be a friction, stiction problems with pivots. So I am contemplating converting to thin metal ribbons for both supports. Also all the recent discussions on convection current noise are relevant. Jim Hannon -------- REPLY, Original message follows -------- Date: Monday, 11-Nov-96 09:12 PM From: Robert L Barns \ CompuServe: (75612,2635) To: PSN \ Internet: (psn-l@.............. Subject: Lehman period Hi gang, The only periods of Lehman seismometers I have heard about are in the 16- 18 sec. range. It would be interesting to hear opinions and/or experiences with Lehman's of longer periods. Since I have little hope of catching local events, long period seismometers are of special interest. The only deterrant to longer periods that I have thought of is possible excessive sensitivity to tilt which might make frequent re-centering necessary. Is the mechanical limit to longer period the stiffness of the suspension wire? I find it a little hard to believe that is a factor since the moment arm for bending the wire is very long. However, the centering force is in the milligram range so wire stiffness might be important. Bob Barns Berkeley Hts., NJ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) -------- REPLY, End of original message -------- _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Erratum: DAMAGE DONE BY THE 1994 NORTHRIDGE, CALIFORNIA, EARTHQUAKE Date: Mon, 11 Nov 1996 21:28:00 -0700 In my recent posting of the abstract, DAMAGE DONE BY THE 1994 NORTHRIDGE, CALIFORNIA, EARTHQUAKE AND THE SPATIAL DENSITY OF SAMPLING STRONG GROUND MOTIONS CRANSWICK, E. U.S. Geological Survey, MS 966, Box 25046, Federal Center, Denver CO 80225, cranswick@.................... I note that an error occurred as a result of exporting the text as a ..TXT-file. The sentence, "This implies a requirement of approximately 2x104 sample points in the San Fernando Valley alone." should read "This implies a requirement of approximately 20,000 sample points in the San Fernando Valley alone." I envision that each of those "20,000 sample points" represents a PSN station in a private residence in the San Fernando Valley. -Edward -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: mgray1@................ (Mike Gray) Subject: Re: Convection Currents in Lehman sensor housing Date: Tue, 12 Nov 1996 10:18:34 -0600 snip >Now I have to seal ALL cracks to keep the bugs out...not the air! > >I am optimistic that sealing the box with the bulb inside will bring >the job to completion. >-Charlie Thompson > ct@....... Charlie, you may want to consider using window screening fabric (real flexible and easy to work with). You may have to add horizontal wood members at the base. These may have to rest on foam rubber strips to get a better seal than what screening without the members would provide. Mike Gray MO Bureau of Emergency Medical Services (Dept of Health) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lyzenga@................. (Greg Lyzenga) Subject: Re: Convection Currents in Lehman sensor housing Date: Tue, 12 Nov 1996 16:36:16 -0800 (PST) >The result is magnitude 10 moth-induced events. My EVENTS directory >has about 20 moth-induced events per night! >> >Now I have to seal ALL cracks to keep the bugs out...not the air! > This reminds me of a problem I've experienced with my Lehman. I've picked up very peculiar harmonic-looking signals sort of like giant microseisms. On investigation, it turned out I was seeing spiders spinning webs on the boom and support structure! - Greg L. |Gregory A. Lyzenga *** (909) 621-8378 |Dept. of Physics, Harvey Mudd College *** fax (909) 621-8887 |Claremont, CA 91711-5990 |http://www.physics.hmc.edu/profs/lyzenga.html _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ct@....... (Charlie & Terri Thompson -- Buda MicroRanch ) Subject: Re: Convection Currents in Lehman sensor housing Date: Tue, 12 Nov 1996 22:27:23 -0600 >Charlie, you may want to consider using window screening fabric (real >flexible and easy to work with). You may have to add horizontal wood >members at the base. These may have to rest on foam rubber strips to get a >better seal than what screening without the members would provide. > >Mike Gray >MO Bureau of Emergency Medical Services (Dept of Health) Mike, Thanks for the screen suggestion. I have laid a platic dry cleaning bag over the top then placed the lid back on with steel bars as weights on the top. The weights help seal the lid to the foam weatherstrip tape along the top edge of the box. Another interesting solution is to simply leave the lights ON in the garage. The moths go to the stronger garage light instead of seeking out the lesser light leaking from the cracks in my Lehman cover. Naturally, I missed the Peru event! I had turned the system off until the mothproofing was complete...arrrrggh! -Charlie _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ct@....... (Charlie & Terri Thompson -- Buda MicroRanch ) Subject: Re: Convection Currents in Lehman sensor housing Date: Tue, 12 Nov 1996 22:31:54 -0600 Oh yes! I recorded spiders before I recorded moths! -c.t. > >This reminds me of a problem I've experienced with my Lehman. I've picked >up very peculiar harmonic-looking signals sort of like giant microseisms. >On investigation, it turned out I was seeing spiders spinning webs on the >boom and support structure! > > - Greg L. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Steve Hammond Subject: Re: Lehman period Date: Wed, 13 Nov 1996 00:55:21 -0800 (PST) On 11 Nov 1996, Robert L Barns wrote: > Hi gang, > The only periods of Lehman seismometers I have heard about are in the 16-18 sec. range. It would be interesting to hear opinions and/or experiences with Lehman's of longer periods. Since I have little hope of catching local events, long period seismometer are of special interest. Bob Barns Berkeley Hts., NJ Hi Bob-- Ted Blank lived in New York and built the basic Lehman design and had GREAT results. The Lehman is ideal for your area because it is designed for long period seismology. You will also stand a good chance of catching 3-4s there in NJ. To give you an example, I live in San Jose, CA and was able to record several of the >4.0 aftershocks following the Northridge quake over 300 miles south of me. You should be able to record event in the mid-Atlantic ridge as well which is something that we in California don't do because of the normal size of the events. You asked about the period. I keep my N/S unit at 21 seconds and then move the damping magnets in to keep it at 30 seconds. If you look at any data with the FSX extension it's from my Lehman units. (BTW I also use the FXZ extension which is from my short period units.) The E/W FSX unit needs LOTS of work to the damping magnets and I just keep it on because it's there. The highest damping I have seen normally used on a Lehman is 48 seconds. I have also run mine at 8 seconds with good results. Regards, Steve Hammond PSN BBS San Jose, Ca 408-226-0675 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Steve Hammond Subject: Re: Convection Currents in Lehman sensor housing Date: Wed, 13 Nov 1996 01:19:25 -0800 (PST) SPIDERS!! I keep these glass windows on the tops of the wood boxes I use because I can flip them open and reach down inside to tweak without pulling the box apart. But what I really hate is when a spider has built a web and I don't see it in the dark. One night I pulled my arm out with the biggest blackest fatest spider hanging from the remainder of his home, just a few inches below my elbow, and he was pissed... Do you know how sticky a spider web is? Anyway-- I've learned that any time the noise level is nice and flat and you look at the display and say "boy this thing is working great," it's not. Either it's a spider or the upper guide wire has broken. I'm also worried about bees, having the outside shed. Regards, Steve Hammond PSN BBS San Jose 408-226-0675 On Tue, 12 Nov 1996, Charlie & Terri Thompson -- Buda MicroRanch wrote: > Oh yes! I recorded spiders before I recorded moths! > -c.t. > > > > >This reminds me of a problem I've experienced with my Lehman. I've picked > >up very peculiar harmonic-looking signals sort of like giant microseisms. > >On investigation, it turned out I was seeing spiders spinning webs on the > >boom and support structure! > > > > - Greg L. > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Re: Spiders Date: Wed, 13 Nov 1996 09:08:59 +0000 > > >This reminds me of a problem I've experienced with my Lehman. I've picked > > >up very peculiar harmonic-looking signals sort of like giant microseisms. > > >On investigation, it turned out I was seeing spiders spinning webs on the > > >boom and support structure! Best e-mail I've read in years! --- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Peru quakes Date: 13 Nov 96 16:16:08 EST Hi gang, I sent my Lehman SDR files on the BIIIG and small Peruvian events to events@.............. This note because I don't know if any notice of these submissions get posted here. These recordings are from a 16 sec Lehman with a 0.08Hz 6-pole active low-pass filter. (Careful--almost left the p off of pass.) Will have to reduce my amp gain because the big one saturated it badly. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: Lehman period Date: Wed, 13 Nov 1996 16:29:28 -0700 Hi Bob and Others When I was setting up my Lehman I found out that anything over 20 seconds would cause several problems. The system was more sensitive to the tilt of the concrete slab the sensor is on, and, if you moved the boom a little it would not go back to the same place. I decided it was better to have a stable sensor over a longer period. Since I have been having problems with the low end frequency response of my Lehman I just checked and found the period to be 7 seconds. A little high, I will play around with it tonight and try and get it back to the 14-16 seconds I thought I was running at. Regards, Larry Cochrane Redwood City, PSN At 09:12 PM 11/11/96 EST, you wrote: >Hi gang, > The only periods of Lehman seismometers I have heard about are in the 16-18 >sec. range. It would be interesting to hear opinions and/or experiences with >Lehman's of longer periods. Since I have little hope of catching local events, >long period seismometers are of special interest. > The only deterrant to longer periods that I have thought of is possible >excessive sensitivity to tilt which might make frequent re-centering necessary. > Is the mechanical limit to longer period the stiffness of the suspension wire? >I find it a little hard to believe that is a factor since the moment arm for >bending the wire is very long. However, the centering force is in the milligram >range so wire stiffness might be important. > Bob Barns >Berkeley Hts., NJ > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ct@....... (Charlie & Terri Thompson -- Buda MicroRanch ) Subject: Re: Lehman period Date: Wed, 13 Nov 1996 22:14:04 -0600 Hi Larry, IF we are correct in our pendulum analysis (dPHI/dT of coil notwithstanding) you will be on a 40 dB/decade rolloff for signals below the natural period. Add the 1st derivative caused by the coil/magnet and the slope is 3x20dB=60dB/decade...this could be the cause of your low-freq sensitivity problem! -Charlie >Hi Bob and Others > >When I was setting up my Lehman I found out that anything over 20 seconds >would cause several problems. The system was more sensitive to the tilt of >the concrete slab the sensor is on, and, if you moved the boom a little it >would not go back to the same place. I decided it was better to have a >stable sensor over a longer period. > >Since I have been having problems with the low end frequency response of my >Lehman I just checked and found the period to be 7 seconds. A little high, I >will play around with it tonight and try and get it back to the 14-16 >seconds I thought I was running at. > >Regards, >Larry Cochrane >Redwood City, PSN > >At 09:12 PM 11/11/96 EST, you wrote: >>Hi gang, >> The only periods of Lehman seismometers I have heard about are in the 16-18 >>sec. range. It would be interesting to hear opinions and/or experiences with >>Lehman's of longer periods. Since I have little hope of catching local events, >>long period seismometers are of special interest. >> The only deterrant to longer periods that I have thought of is possible >>excessive sensitivity to tilt which might make frequent re-centering necessary. >> Is the mechanical limit to longer period the stiffness of the suspension wire? >>I find it a little hard to believe that is a factor since the moment arm for >>bending the wire is very long. However, the centering force is in the >milligram >>range so wire stiffness might be important. >> Bob Barns >>Berkeley Hts., NJ >> >> >>_____________________________________________________________________ >> >>Public Seismic Network Mailing List (PSN-L) >> >>To leave this list email listserver@............. with the body of the >>message: leave PSN-L >> > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jeff Batten Subject: Getting a wider bandwidth with your lehman. Date: Wed, 13 Nov 1996 20:51:19 -0800 There are several ways to extend the bandwidth of a lehman to get a good response to both long period and short period waves. For long period wave monitoring just go with a period of six seconds, and use a low pass filter with a period of 20 seconds. Turn up the gain on your amp and you will have no trouble seeing 20s surface waves. I have found it much easier to do this then trying to get a period of over 12 sec messing with the horizontal boom. On way to turn your horizontal into a broadband instrument is to have one amp for short period waves, and one for long period waves. Then just add the voltages with a summing amp. Then you will have a seismometer that records the small local events well, and the bigger distant quakes. Jeff Jeff Batten - Research Engineer Caltech Seismo Lab 818-395-6965 Fax-818-564-0715 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Steve Hammond Subject: Re: A Few good used books to Consider (fwd) Date: Thu, 14 Nov 1996 00:02:10 -0800 (PST) Sure will Bob- Some time ago, I was able to get a copy of USGS report 69 from Carpe diem books entitled, The Earthquakes at Yakutat Bay, Alaska in September 1899. It was published in 1912 and was written by Tarr and Martin with the preface by G.K. Gilbert. The report includes a fold-out map of Alaska dataed 1909 showing the damage zone. According to the report, the earthquake caused deformation over 1,000 sq. miles, had a maximum uplift of 47 feet. It also caused the Muir Glacier to do a rapid retreat and several others to move forward. As your from Alaska, I was wondering if you (or John Lahr) knew of any modern day estimate of its size? Regards, Steve Hammond PSN BBS San Jose California 408-227-0675 On Wed, 13 Nov 1996, Bob Hammond wrote: > > to Steve Hammond: > > I think your posting of the book list to the PSN group is excellent! I only hope I can get my > hands on a few of them before everyone else. > > thanks, > > Bob Hammond > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Yukatat 1899 earthquakes Date: Thu, 14 Nov 1996 07:51:54 +0000 Steve Hammond wrote: > > Sure will Bob- Some time ago, I was able to get a copy of USGS report 69 > from Carpe diem books entitled, The Earthquakes at Yakutat Bay, Alaska in > September 1899. It was published in 1912 and was written by Tarr and > Martin with the preface by G.K. Gilbert. The report includes a fold-out > map of Alaska dataed 1909 showing the damage zone. According to the > report, the earthquake caused deformation over 1,000 sq. miles, had a > maximum uplift of 47 feet. It also caused the Muir Glacier to do a rapid > retreat and several others to move forward. > > As your from Alaska, I was wondering if you (or John Lahr) knew of any > modern day estimate of its size? > There were a series of strong earthquakes that registered 7.0 or stronger across the northeastern Gulf of Alaska in 1899. The first quake struck on September 4 between Yakatage and Icy Bay and is estimated to have registered Ms 7.9. The second and third quakes occurred about 70 miles to the east and about 20 mile north of Yukutat Bay on September 10 (1704 and 2141 UTC) and measured Ms 7.4 and Ms 8.0, respectively. The fourth quake registered Ms 7.0 and happened September 23 about 25 miles west of Cape Yakatage. (Source: Neotectonics of North America, Seismicity of contential Alaska, Page and Others, 1991) Yeah, uplift was dramatic. --- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: bob@................. (Bob Hammond (USGS-AVO Geophysicist)) Subject: Re: 1899 Yakutat Bay earthquakes Date: Thu, 14 Nov 1996 07:52:53 -0900 Steve Hammond: Charlie Watson quoted the same info I would have given you and is correct on the 1899 Yakutat Bay quakes. I had the opportunity to fly low up the Fairweather Fault in that area and the scars left by the landslide and tsunami are clearly visible. The accounts of people in the area during the quake are interesting reading. Want to sell your Tarr and Martin USGS Report 69? regards, Bob Hammond _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) Subject: Re: A Few good used books to Consider (fwd) Date: Thu, 14 Nov 1996 11:01:52 -0900 > Date: Thu, 14 Nov 1996 00:02:10 -0800 (PST) > From: Steve Hammond > Subject: Re: A Few good used books to Consider (fwd) > > Sure will Bob- Some time ago, I was able to get a copy of USGS report 69 > from Carpe diem books entitled, The Earthquakes at Yakutat Bay, Alaska in > September 1899. It was published in 1912 and was written by Tarr and > Martin with the preface by G.K. Gilbert. The report includes a fold-out > map of Alaska dataed 1909 showing the damage zone. According to the > report, the earthquake caused deformation over 1,000 sq. miles, had a > maximum uplift of 47 feet. It also caused the Muir Glacier to do a rapid > retreat and several others to move forward. > > As your from Alaska, I was wondering if you (or John Lahr) knew of any > modern day estimate of its size? > > Regards, > Steve Hammond PSN BBS San Jose California 408-227-0675 Hi Steve, You have a classic and collectable publication! We compiled a listing of source parameters of magnitude 7.0 or greater earthquakes for continental Alaska for the Decade of North American Geology (DNAG) volume, Neotectonics of North America, GSA, 1991. There are five events listed for 1899 and one for 1900: Year Mo Dy Lat Lon Ms 1899 07 14 60 150 7.2 1899 09 04 60 142 7.9 1899 09 10 60 140 7.4 1899 09 10 60 140 8.0 1899 09 23 60 143 7.0 1900 10 09 57.09 153.48 7.7 The magnitudes are from a paper by Abe (1981) in Physics of the Earth and Planetary Interiors, v. 27, p. 72-92. The location of the first event is extremely uncertain, being based on felt reports from Tar and Martin (1912). JCLahr ################################# John C. Lahr ################################ U.S. Geological Survey ############################### c/o Geophysical Institute ############################## 903 Koyukuk Drive ########################################################### ########################################################### P.O. Box 757320 ################################ Fairbanks, AK 99775 ################################# Phone: (907) 474-7997 ################################## Fax: (907) 474-5618 ################################### lahr@........ #################################### _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Mark Wilson mark@.............." Subject: I'm jazzed Date: Thu, 14 Nov 1996 17:10:12 -0800 (PST) About 2 years ago on the quake L discussion list, I had mentioned an experiment using a hall effect transducer. I have been out of the area but am back, and noticed quite a few discussions in this group about the Hall effects transducer and some of the interesting results. I am going to sift through them and see. My seismo has been sitting in the garage all of this time. I did realize at the time that the HET would pickup true movement without acceleration, but that is where I left it, interesting thought about the EMF from the earth... I will read some more... Great to be here! I know very little about seismology or geology, but love to tinker with electronics and did ELF stuff in the Army. ********************************************************************* - Mark Wilson --- mark@.............. ********************************************************************* _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) Subject: Magnitude 7 Alaskan Earthquakes Date: Thu, 14 Nov 1996 19:51:06 -0900 After Steve Hammond's question about Alaskan earthquakes, I decided to put the DNAG table of magnitude 7 and large events on the web so that they could be referenced easily. The table it linked to my (rather pathetic) home page: http://www.giseis.alaska.edu/Input/lahr/lahr.html JCLahr ################################# John C. Lahr ################################ U.S. Geological Survey ############################### c/o Geophysical Institute ############################## 903 Koyukuk Drive ########################################################### ########################################################### P.O. Box 757320 ################################ Fairbanks, AK 99775 ################################# Phone: (907) 474-7997 ################################## Fax: (907) 474-5618 ################################### lahr@........ #################################### _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Steve Hammond Subject: Re: Magnitude 7 Alaskan Earthquakes Date: Fri, 15 Nov 1996 01:23:31 -0800 (PST) Thanks Bob, Charles, and John for the info on the 1899 Alaskan quakes. I have printed all the note and I slipped them into the rear map page folder making them a permenant part of the report. No thank Bob on the offer to sell it, I really find the old publications to be remarkable. -----John--- I tried the WWW address but could only reach HTTP://WWW.giseis.alaska.edu/ but got a bad address message at the Input/.... Did I do it wrong? Thanks-0- Steve On Thu, 14 Nov 1996, Dr. John Lahr wrote: > After Steve Hammond's question about Alaskan earthquakes, I > decided to put the DNAG table of magnitude 7 and large events on > the web so that they could be referenced easily. The table > it linked to my (rather pathetic) home page: > > http://www.giseis.alaska.edu/Input/lahr/lahr.html > > JCLahr > ################################# John C. Lahr > ################################ U.S. Geological Survey > ############################### c/o Geophysical Institute > ############################## 903 Koyukuk Drive > ########################################################### > ########################################################### > P.O. Box 757320 ################################ > Fairbanks, AK 99775 ################################# > Phone: (907) 474-7997 ################################## > Fax: (907) 474-5618 ################################### > lahr@........ #################################### > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Steve Hammond Subject: Re: PSN goodies... Date: Sat, 16 Nov 1996 11:57:01 -0800 (PST) Yeah-- We (via D. Darby's help) have given a fellow and his wife (PSN people) the OK to use the PSN name and LOGO "PSN" on ballcaps and shirts. That was part of the note Ed Cranswick posted about the trademark of the PSN. They are still getting their act together but I'm waiting to see if I can put in a Christmas order myself for one of each. WHERE DOES IT STAND Mrs. D.? Are they going to have a catalog before Christmas? Regards, Steve On Fri, 15 Nov 1996, Ken Navarre wrote: > > So, the other day we had some information on the list that perhaps some > T-shirts and ball caps would be available with a PSN logo. What's the > status??? Is it a go or has our unofficial nationwide "administrator" > squished the deal?? :) > > Amatuer silkscreening is just about as much a pain as is amatuer > seismology. But it does take up less space! I wanna PSN ball cap! :) > > Ken > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Roger Griggs Subject: 1872 Owens Valley Quake Scarp Date: Sat, 16 Nov 1996 17:33:11 -0800 Hi Folks, I thought I might share a recent experience I had on a weekend adventure traveling down route 395 on the east side of the Sierra Nevada mountian range. In particular, a stop at the Lone Pine site of one of the largest and strongest quakes to hit California in the last 200 years. There is a easily accessable scarp left in part by the 1872 quake that accounted for about 5 ft of the vertical displacement. The other 18 or so was produced by two earlier comparable sized quakes at intervals of between 5000 to 10,500 years ago. It is estimated that the Sierra's rose 13ft in height during those first few hours. The 7.75 M (HHT-USGS) 1872 quake had a horizonal movement that pushed the land east of the fault about 16ft southward. 52 of the 59 buildings in Lone Pine were completely destroyed killing 27 people. There is a mass grave monument just north of town where 16 of the victims are buried. To get to the site take Whitney Portal road west out of Lone Pine about 0.7 miles. As soon as you cross over an aqueduct, make a hard right up a dirt road leading north. There is a big sign that LA Water put up saying no overnight camping is allowed. There are no fences or gates. Stay on the dirt road 1/2 mile as it trends slightly uphill and crosses 2 small irragation pipes and turns back east (right) towards the aqueduct. The road drops into a depression a few yards down a slight incline at a low ridge of bolders. To your left is the scarp. Be mindful of broken beer bottles as this is probably a local drinking spot. As I stood there, staring at the gaping slice of earth, I took some time to ponder what it must have been like on that crisp March night with the ground moving directly below my feet. A very inspiring moment that everyone should experience. As luck would have it the famed naturalist John Muir was living in Yosemite on the other side of the Sierran crest, about a 100 miles to the northwest, at the time of the quake. He was perhaps one of the vary few eye-witnesses of the quake. This is just his brief discription of the effects of the earthquake on the surrounding mountians as Muir wrote them down: "It was a calm moonlit night and no sound was heard for the first minute or so, save low, muffled, underground bubbling rumblings, and the whispering and rustling of the agitated trees, as if Nature were holding her breath. Then suddenly, out of the strange silence and strange motion there came a tremendous roar. The sound was so tremendously deep and broad and earnest, the whole earth like a living creature seemed to have at last found a voice and to be calling to her sister planets. The shocks were so violent and varied, and succeeded one another so closely, that I had to balance myself carefully in walking as if on the deck of a ship among waves. For a minute or two the shocks became more and more violent flashing horizontal thrusts mixed with a few twists and battering, explosive,upheaving jolts. Eagle rock, on the south wall, gave way and I saw it falling in thousands of giant bolders to valley floor" There is much more tantilizing paragraphs to his writing but I will try and keep the size of this thing below huge. I would suggest a couple of good books that have this and much more information on the Owens Valley, the 1872 quake and it's geology. Geology of the Sierra Nevada by Mary Hill ISBN: 0-520-02698-5 (prbk)$11.95 Deepest Valley, Guide to Owens Valley by Pual Baterman 0-931378-14-1 (prbk) $14.95 Roger Griggs Oakley Seismic Station _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: 1872 Owens Valley Quake Scarp Date: Sun, 17 Nov 1996 22:38:33 -0700 Roger- The first California earthquake I chased was near there, the 1980 25 May Mammoth Lakes event(s: three mag 6+'s on Sunday and a mag 6.4 on Tuesday), and it's been all downhill since then. We then used Sprengnether DR-100 portable autonomous digital seismographs deployed within a 15 km radius of Mammoth Lakes to record aftershocks for two weeks. I liked your quotes fom Muir. -Edward -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: BZIMMERMAN@............ Subject: Information on Eastern U.S. Events Date: Mon, 18 Nov 1996 10:40:15 -0500 (EST) Greetings from the snow-bound shores of Lake Erie. I recorded what looks like a very nice (but small) P-wave on 11/14/96 at 22:03:51 UT. I would like to determine the source of this event. The event was recorded by a few seismographs in the Great Lakes region from the Canadian National Seismograph Network. Studying the hourly records from the Canadian Network, I've determined that this is a local event and most likely occurred somewhere south of my location (41:52:30N 80:07:30W). I've looked at all the obvious quake lists from Canada and the U.S.(including the Central, Southern Appalachia, and New England lists from the USGS). Did anyone else record this event? Where else can I look to determine the source ? (It is possible that it is a mine/quarry blast rather than a quake) Thanks in advance for any help. Brian S. Zimmerman Department of Geosciences Edinboro University of Pennsylvania Edinboro, PA 16444 Phone: (814) 732-2207 Email: BZimmerman@............ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Spectacular Earthquake Photos Date: Mon, 18 Nov 1996 17:33:42 +0000 Along the same lines of dramatic exposures of 1872 Owens Valley fault displacements, I was researching an earthquake for the cover photograph for the October 1996 pre-issue of EQNEWS and came across some photos of the October 28, 1891, Nobi, Japan, 8.0 earthquake. A spectacular photo was taken in the Neo Valley, near the village of Midori, showing a 6 m vertical displacement across a road with a person walking on the down thrown side. I have put a copy of the image at the following URL: http://www.seismo-watch.com/EQSERVICES/Newsletter/EQNEWS9610.html A thumbnail of the October 1996 pre-issue cover can be see at: http://www.seismo-watch.com/EQSERVICES/Newsletter/Newsletter.html Creating the pre-issue has been rewarding and I am looking forward to the inaugural issue next month. For the November 1996 issue, I have another great photo of the November 10, 1946, earthquake in Peru which has a man standing in front of a 3.5 meter scarp. I am also working on a photo of either a trench log at Pallet Creek or a set of tree rings showing the disturbance from the 1812 San Bernardino earthquake for the December 1996 issue. If anyone has some photos of spectular fault displacements or interesting paleoseismic assessments and would like to offer them for publication, please contact me and we can work out the details. Enjoy! --- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Rev. Bob Shannon" Subject: The Geysers Date: Mon, 18 Nov 1996 17:57:47 -0800 (PST) Today we had a 3.9-4.0 at the Geysers, evidently an unusual event according to a USGS employee who looked it up and found only 5 M> Q's at the Geysers since 1980. The Geysers have been an area of interest in EQ precursors. Any thoughts about todays Q? Also note that two of my newsletter readers who keep daily track of various factors, have noticed a large increase in well water levels..One in Southern Ca has had a 43 foot increase in 7 days with little to no rainfall..(*This person lives in the mountains N of LA) The other west of the Geysers has not come in with numbers... Bob _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Ken Navarre Subject: Re: Spectacular Earthquake Photos Date: Mon, 18 Nov 1996 20:18:54 -0800 (PST) On Mon, 18 Nov 1996, Charles Watson wrote: > Along the same lines of dramatic exposures of 1872 Owens Valley fault > displacements, I was researching an earthquake for the cover photograph for > the October 1996 pre-issue of EQNEWS and came across some photos of the > October 28, 1891, Nobi, Japan, 8.0 earthquake. (snip) > If anyone has some photos of spectular fault displacements or interesting > paleoseismic assessments and would like to offer them for publication, please > contact me and we can work out the details. My significant other was in salt Lake City for a few days last month and wandered into an antique shop. She has this obsession with "stereo viewers" and stereo view cards (as well as viewmaster...). Anyway, she happened upon a great stereoview card that shows surface ruptures in the Sobrante Hills near Berkeley following the 1906 San Francisco earthquake. It's titled (oddly enough), "Remarkable Earthquake Fissures in the Sobrante Hills near Berkeley, california"... Not too great a deal for publication unless the readers also happen to have one of the old wooden stereo viewers lying around... :( Still, it was a neat find! Ken _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) Subject: Re: Spectacular Earthquake Photos Date: Tue, 19 Nov 1996 09:41:43 -0900 Ken, I'm stereo obsessed as well, and do have some stereo viewers. It would be interesting to put the pair up on a web page at about the same scale as the originals for viewing directly from the screen. JCLahr ################################# John C. Lahr ################################ U.S. Geological Survey ############################### c/o Geophysical Institute ############################## 903 Koyukuk Drive ########################################################### ########################################################### P.O. Box 757320 ################################ Fairbanks, AK 99775 ################################# Phone: (907) 474-7997 ################################## Fax: (907) 474-5618 ################################### lahr@........ #################################### _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ct@....... (Charlie Thompson) Subject: Eastern Kashmir Mag 7 Quake Bagged! Date: Tue, 19 Nov 1996 17:22:46 -0600 I bagged the Eastern Kashmir 7.1Ms quake this morning. Interesting waveform. The P wave is missing because I am just inside the P wave shadow zone at about 103 degrees. This is my distance record! 7931 miles from Buda, Texas. 96/11/19 10:44:45 35.2N 78.2E 7.1Ms Eastern Kashimr Larry, refresh me on how to upload the datafile to PSN, I could not find your memo on the procedure. Did anyone on the east coast record this quake and see the P wave arrival? California is the wrong direction and is further into the P wave shadow I think. -Charlie Thompson Buda, Texas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Spectacular Earthquake Photos Date: Tue, 19 Nov 1996 14:59:25 -0700 Ken Navarre wrote: > > On Mon, 18 Nov 1996, Charles Watson wrote: > > > Along the same lines of dramatic exposures of 1872 Owens Valley fault > > displacements, ... Something I neglected to add on my last post on the subject, "The first California earthquake I chased was near there, the 1980 25 May Mammoth Lakes event(s: three mag 6+'s on Sunday and a mag 6.4 on Tuesday)", was that these events produced a 15-cm offset in the dirt road that goes over the Sierra Range-front scarp and up into McGee Creek canyon where we had a portable autonomous digital seismograph whose tapes had to be changed each day. Whether the offset was truly tectonic or a slump feature caused by the shaking, I don't know, but it was a big bump in the road that produced a big jolt and caused me to hit my head on the roof of the pickup truck every morning when we drove over it at 30 mph in our rush to service stations. It was a very vivid reminder that I was in California studying "real" earthquakes and not the magnitude 3 "mainshocks" in the Adirodack Mountains of northern New York State that I chased while I was in graduate school. -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: BZIMMERMAN@............ Subject: Re: Eastern Kashmir Mag 7 Quake Bagged! Date: Wed, 20 Nov 1996 10:33:21 -0500 (EST) Charlie: We picked up the Kashmir quake here in Edinboro (great circle distance 100.4 deg) just surface waves, no P wave. I looked at records from SUNY Binghamton which are similar in terms of the phases that were recorded. Our seismogram can be viewed at the following URL: http://coop20.geos.edinboro.edu/~brianz/seismo.html I plan to upgrade this site over the term break to make our PSN format quake files available for download. Brian S. Zimmerman Department of Geosciences Edinboro University of Pennsylvania Edinboro, PA 16444 Phone: (814) 732-2207 Email: BZimmerman@............ On Tue, 19 Nov 1996, Charlie Thompson wrote: > I bagged the Eastern Kashmir 7.1Ms quake this morning. Interesting > waveform. The P wave is missing because I am just inside the P wave > shadow zone at about 103 degrees. This is my distance record! 7931 > miles from Buda, Texas. > > 96/11/19 10:44:45 35.2N 78.2E 7.1Ms Eastern Kashimr > > Larry, refresh me on how to upload the datafile to PSN, I could not > find your memo on the procedure. > > Did anyone on the east coast record this quake and see the P wave arrival? > California is the wrong direction and is further into the P wave shadow I > think. > > -Charlie Thompson > Buda, Texas > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Rev. Bob Shannon" Subject: Unusual event? Date: Wed, 20 Nov 1996 10:14:25 -0800 (PST) Folks; I received the following message from a seismograph owner in Salem Oregon. We wonder is someone might be able to decipher the readings she was getting on Sunday last. Bob Forwarded follows: Our seismograph has been acting very strangely since early Sunday morning. At least that is when we first noticed it. Steve went into the office at about 5:00 am Sunday, and the seismograph was recording a saw-tooth-like pattern of about 20 cycles per minute, but they were not large enough to trigger the "save" program on the computer. These have continued for over 24 hours. Something is definitely going on, maybe in the Gorda Ridge area. The last time we saw something even remotely like this, was when there was magma flow at Gorda Ridge. BUT, that event only lasted about 2-3 hours on the seismograph. There is no other reason for the seismograph to be recording this way: we have checked all other possible variables. Salem _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Cristiano Subject: bushing Date: Wed, 20 Nov 1996 12:04:48 -0700 Darrell Collins, Re: bushing for boom weight. I went to the hardware store and got two small pvc elbows and a small pvc slip couple. The inside diameter of the elbow male end fit the 5/8" threaded rod and the outside diameter of the slip couple fit into the hole in the 5lb. barbell weight. I glued the elbows into the slip couple and after it dried hacksawed the slip couple to size. Wound up with a bushing for about $1.50. Regards, Jim Cristiano cristiano@........... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Warren Shedrick" Subject: Re: Unusual event? Date: Wed, 20 Nov 1996 12:39:23 +0000 > Date: Wed, 20 Nov 1996 10:14:25 -0800 (PST) > From: "Rev. Bob Shannon" > To: PSN Mail List > Cc: vicarbob@........... > Subject: Unusual event? > Reply-to: PSN-L Mailing List > Folks; > I received the following message from a seismograph owner in Salem > Oregon. We wonder is someone might be able to decipher the readings she > was getting on Sunday last. > Bob > Forwarded follows: > > > > Our seismograph has been acting very strangely since early Sunday > morning. At least that is when we first noticed it. Steve went into > the office at about 5:00 am Sunday, and the seismograph was recording > a saw-tooth-like pattern of about 20 cycles per minute, but they were > not large enough to trigger the "save" program on the computer. These > have continued for over 24 hours. Something is definitely going on, maybe > in the Gorda Ridge area. The last time we saw something even remotely > like this, was when there was magma flow at Gorda Ridge. BUT, that event > only lasted about 2-3 hours on the seismograph. There is no other > reason for the seismograph to be recording this way: we have checked > all other possible variables. > > Salem > > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L I live in Salem, Or. And have been slowly building a seismo monitor station here. Is there any way I can contact the person who sent the message or obtain a list of other stations in the Oregon area. Thank you Warren Shedrick _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ct@....... (Charlie Thompson) Subject: Re: Unusual event? Date: Wed, 20 Nov 1996 15:25:11 -0600 I would check for spiders, bugs, and other non-seismic stimuli. I have seen an oscillation here but it started after wrapping the top of my Lehman box with platic dry cleaner bags. I plan to remove the plastic to see if the periodic component is thermal oscillation of some variety instead of actual micro-seisms. -Charlie Thompson Buda, Texas > >Our seismograph has been acting very strangely since early Sunday >morning. At least that is when we first noticed it. Steve went into >the office at about 5:00 am Sunday, and the seismograph was recording >a saw-tooth-like pattern of about 20 cycles per minute, but they were >not large enough to trigger the "save" program on the computer. These >have continued for over 24 hours. Something is definitely going on, maybe >in the Gorda Ridge area. The last time we saw something even remotely >like this, was when there was magma flow at Gorda Ridge. BUT, that event >only lasted about 2-3 hours on the seismograph. There is no other >reason for the seismograph to be recording this way: we have checked >all other possible variables. > >Salem > > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Seismo-Watch Begins Television Production Date: Wed, 20 Nov 1996 13:29:21 +0000 Colleagues, It is with great honor to announce that Advanced Geologic Exploration (AGE), publishers of Seismo-Watch, Earthquake Information Services, and Sierra Nevada Community Access Television (SNCAT) have completed the final arrangements to present a new television series, the Seismo-Watch Weekly Earthquake Report. Beginning Saturday, November 30, 1996, a sequence of non-audio earthquake graphic panels will be shown on SNCAT¹s electronic billboard to the Reno/Sparks metropolitan audience via four public access cable channels. The sequence of earthquake panels will be included in a stack of community service messages and updated once a week. The stack cycles through its contents about once every 20 or 30 minutes, indicating the earthquake sequence potentially will be seen 48-96 times a day or in excess of 300 times per week, barring preemption of other important community informat initial sequence will consists of the following panels: 1) an introduction panel highlighting the sequence content 2) an underwriters or sponsorship panel presenting sponsors of the program 3) a graphic showing the M+5.0 worldwide earthquake activity of the previous week; 4) a graphic showing the weekly M+1.0 earthquake activity from the northwestern Nevada and eastern California region, including the very active Mammoth Lakes and Long Valley caldera 5) an information source panel 6) a exit panel showing the AGE contact number for more information. SNCAT operates four community access channels (two on TCI Cablevision (16 and 13) and a pair on Continental Cablevision (20 and 30)) within the Reno/Sparks, Nevada, metropolitan area, with a combined potential viewership of 221,000 people from 65,000 homes. SNCAT has an excellent In agreement with Community Access Television requirements, there will be no advertising or commercial content, however, underwriting or sponsorship programs will be allowed. Each contributing organization or company will be noted on the underwriters/sponsorship panel and will be allowed an one-line, non-audio organization or company slogan, similar to other public broadcasting formats. AGE is celebrating its fifth year of publishing Seismo-Watch earthquake graphics. With service to 28 newspapers in the western United States showing weekly or monthly regional earthquake graphics, it has gained a potential followship of over 7.5 million people. They also produced EQNEWS, a comprehensive monthly bulletin of worldwide and regional earthquake activity, scheduled will continue the acclaimed tradition set by the Seismo-Watch Newsletter in December, 1996. Other earthquake information services for the media and the general public can be obtained from their worldwide site at: http://www.seismo-watch.com or by calling their contact number below. --- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Darrell Collins Subject: Re: bushing Date: Wed, 20 Nov 1996 16:53:08 -0700 (MST) At 12:04 PM 11/20/96 -0700, you wrote: >Darrell Collins, > Re: bushing for boom weight. > That sounds like a great solution, quick, cheap, effective! What more could one want? Do keep me in mind if you need anything else. Thanks, Darrell _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Seismo-Watch/SNCAT message glitches Date: Thu, 21 Nov 1996 23:19:27 +0000 Oh, bother. I see my Netscape Mail failed to correctly accept the paste message from Word Perfect again and truncated some sentances. Humm... Instead of resending the corrected message about the Seismo-Watch/SNCAT television agreement, just know this a wonderful new horizon of bringing current earthquake information to a larger audience. Both SNCAT and I am very excited about the proposition and are eager to begin production. Those aware of the Seismo-Watch/TCI proposition can rest asure this option is still open, but is moving more slowly. A production schedule should be announced in early-mid 1997. Thanks for everyones support and if the format proves successful, as preliminary tests suggest, other community access television networks capable of accepting graphics into their electornic billboard can be quickly incorporated into the system. .....going to have to check that Netscape Mail paste better next time..... --- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Two files?? Date: 22 Nov 96 14:08:18 EST Larry Cochrane, HOMEFAQ.TXT sez to ftp.andreas.wr.usgs.gov/pub/psn to get SEISAMP.GIF and TELEMETRY.DOC. I could not find those files there or on the Memphis BBS 901-360-0302. It would probably be useful to have them on psn.quake.net. I might like to try to rec. some of the local telemetry data. Where can I find frequencies and other details about telemetry around here? Does anyone on this net know of sources where one might buy surplus professional long period seismometers? It seems that there might be some around because of the big effort to change to broad-band force-feedback sensors. Bob Barns Berk. Hts., NJ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Tinkler@....... Subject: Power of a Quake Date: Fri, 22 Nov 1996 23:18:22 -0500 Came across this discription of a earthquake in the magazine "The Watchtower "that had happened back in 1950, in the region of the Himalayas. In my book "An introduction to the theory of Seismology by K.E. Bullen" on page 272 stated it had been given a magnitude of 8.7 by Mr. Richter and Gutenberg, and is also mentioned in one of my Scientific America handbooks dating back to 1957. Does anybody else have any info on it. It amaze's me the power that would have been generated that would be able to move 100's of millions of tons of earth and rock straight up. *** w51 4/1 201-2 "Earthquakes in One Place After Another" *** "Earthquakes in One Place After Another" LAST August 15 the severest earthquake of the twentieth century, the "biggest of the present generation", the "most drastic natural upheaval in a populated place that the world ever has known", was centered in northeastern India, Assam, Nepal and southern Tibet. So violent was that quake that all seismographs throughout the world joined the rhythm in a wild and dizzy dance. Many were completely knocked out. The one at Istanbul, Turkey, was broken, and at Boston College, on the opposite side of the globe, the seismograph ran right off the recording paper. When the shock-wave reached Milwaukee, Wis., 11,000 miles away, the water in a deep well set a new record by jumping 54 inches. Radio and press services flashed out the news, and the people instinctively knew that once again a catastrophe of great magnitude had struck. Somewhere beneath The Himalayas, the world's highest mountain range, there was a slipping of the subterranean rock, which in turn threw 30,000 square miles of earth's surface into convulsions. Some of the rivers of the region disappeared; others changed their courses. The Brahmaputra, one of the greatest rivers in the world, put on a strange and terrible act, as the tilting and rocking of the land caused it first to recede and then to rush down in mad fury. At places it overflowed its banks and swept across open country like an ocean. Its tributary, the Subansiri, spread ruin through 1,500 villages. Whole mountains tumbled down, burying villages and stopping up rivers in the valleys below. Then when the artificial lakes that were thus formed burst through the earthen dams they roared down the valleys, taking everything with them: massive trees, mighty jungles and all creatures in them. What a frightful sight-the bodies of dead elephants, tigers, monkeys and other wildlife, as well as human victims-all borne on the crest of the raging waters! At other places great chasms opened up and subterranean waters were added to the peril. Granaries were destroyed, leaving many areas threatened with starvation. Fish by the thousands in the streams were either buried in landslides of mud or suffocated by sulphurous gases from the earth's fiery internal regions. Spouting volcanoes reddened the skies for days as they joined in this rebellion of nature, which was rated as "one of the greatest natural catastrophes" in Assam's history. It is almost unbelievable, but majestic Mt. Everest, the highest peak in the world, was literally raised up another 198 feet in altitude! All communications were completely cut off. Roads and streams literally vanished and large sections of railways were left dangling in the air. Telephone and power lines over a great area were knocked out. Panic broke out throughout northern India and Burma, including Calcutta, and thousands either ran screaming through the streets in their terror or huddled together in prayer to their demon gods. And as nearly 200 tremors and aftershocks continued daily to rock the country for more than a month, the lives and activity of the already fear-stricken people were further numbed. Counting some of the cost, damage to the tea plantations alone amounted to $4,000,000. Thousands of houses were destroyed, 50,000 head of cattle were killed, about 5,000 people lost their lives, and 5,000,000 others suffered from the month-long series of quakes. But the tabulation of such cold figures tells very little of the pain and misery and woe wrought by these superhuman earthshaking forces. IS THERE AN EARTHQUAKE EPIDEMIC? _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re:Two files??, Telemerty boards and Peru event Date: Fri, 22 Nov 1996 21:27:29 -0700 Hi Bob and others, At 02:08 PM 11/22/96 EST, you wrote: >Larry Cochrane, > HOMEFAQ.TXT sez to ftp.andreas.wr.usgs.gov/pub/psn to get SEISAMP.GIF and >TELEMETRY.DOC. >I could not find those files there or on the Memphis BBS 901-360-0302. > It would probably be useful to have them on psn.quake.net. I'm not sure what's in seisamp.gif but I did placed a copy of Ken Navarre's article on the psn.quake.net system. I renamed the file to telemtry.txt so web browsers will load it as a text file. The URL to the file is http://psn.quake.net/info/telemtry.txt I also place a link to this file on the web page for my demodulator board at http://psn.quake.net/telebrd.html. > I might like to try to rec. some of the local telemetry data. Where can I >find frequencies and other details about telemetry around here? That's a hard one, Ken and I have a list for local sensors (Northern California) but that's about it. The first thing to do is see if you even have a sensor array around you. I seem to recall the Ed Cranswick said that there was an array around NJ. The next thing to do is see if you can receive, using a police scanner, one or more of the sensors using the frequency range / list in the telemtry.txt file. The thing to listen for is a continuous tone or several continuous tones. Each audio channel can have up to 8 tones or channels on it. For more info on the frequencies and spacing see the telebrd.html page. If you can receive one of the stations the next thing you need to is make or buy a demodulator board. To make a simple demodulator you will need to make a narrow band-pass filter (if there are more then one tone on the channel) and a frequency to voltage converter. I us a CD4046 phase lock loop chip on my board. The output of the PLL should then do thru a low-pass filter and then into your A/D card or chart recorder. If you don't want to make your own demodulator board I will be more then willing to sell you one of mine . I just had more blank PC boards made so I can sell them again. I needed too what until I got a few orders before I could make more boards. My board allows you to receive any one of the 8 tones on the audio channel by changing a switch on the board. This way I don't need to have 8 different versions (one for each tone) of the board. My board is similar to a radio receiver by converting each input tone to a common frequency (~5khz) and then running the signal thru a narrow band pass filter, a MAX 268 switched cap filter, and then into the CD4046 PLL. The output of the PLL then goes into a 16 pole low-pass filter using 2 MAX 291 switched cap filters. The low-pass filter's upper frequency is selectable. I run my boards with a 10 hz setting. The output of the low-pass filter then feeds a output op-amp and then into the A/D card. My board cost $130.00 and if it turns out you can't use the board I will be more then happy to refund the money. Since I live fairly close to the USGS in Menlo Park I an "lucky" to be able to receive 5 or 6 different rf channels. Some of the transmitters sites are also used as repeaters for other sensor sites. What you can usually receive using one of the telemetry channels is a short period vertical or a few short period horizontal sensors. Most are hi gain and are located in locations that may have less local ground noise then a sensor located in you home. I am currently monitoring 5 USSG sensors using 3 police scanners. Each scanner has a high gain yagi antenna mounted on the top of my roof. Since the sensors are short period they are not very good for teleseismic events except for picking up the P wave of the event. Because the stations I am monitoring are hi gain I am able to pick up local events as small as 1.3 to 2.0 depending on how far away the event is. The problem is they tend to saturate with any over 3.0. Using this type of telemetry signal you only get 10 or 11 bits of dynamic range. I like using the USGS sensor as a way of triggering my SDR data loggers. With SDR you can set it up so it takes 2 or more channels to go past the alarm settings before the system will sound the alarm and save a PSN format event file. This really cuts down on the false alarms. > Does anyone on this net know of sources where one might buy surplus >professional long period seismometers? It seems that there might be some >around because of the big effort to change to broad-band force-feedback sensors. Can't help you on this one. But before you spend a lot on money on a used commercial sensor I would consider making a SG sensor. The other day I logged into the berkeley.edu system and download some waveforms from several of their broadband sensors for the Peru 7.3 event on 11/12. I wanted to see the difference between their commercial sensors and my under $200.00 sensor. They use STS/1 or STS/2 broadband sensors (whatever that is) with a 5 hz upper range for the STS/1 and 20Hz for the STS/2. I picked two of the closest stations to me, the Berkeley sensor BKS and the Stanford sensor JRSC. For more info on their broadband sensor see: http://quake.geo.berkeley.edu/ftp/pub/doc/broadband.stations. I think you will see that my SG sensor remarkably produced a seismogram very similar to theirs. I used two of there sensor just to get an idea of the differences between two different sites using the same sensor. If you would like to compare the event files yourself you can download the following files: My SG sensor event file for the Peru event is 961112a.lc3. I also had another SG sensor going at the time. This sensor was in test at the time and will soon be online at a friends house in Ben Lomond California. The event file name is 961112a.sg1. Both sensors where orientated N-S. For the commercial sensor the files are as follows: Berkeley Sensor: Stanford Sensor Orientation: 961112N.BKS 961112N.JRS N-S 961112E.BKS 961112E.JRS E-W 961112Z.BKS 961112Z.JRS Z All of the files are in this months event file directory at ftp://psn.quake.net/quakes/9611/ or you can use you http://psn.quake.net/quake/9611/index.html. The files on the Berkeley system where converted from SAC binary to PSN format using WinQuake. If you would like to see the original SAC files, I made a directory called /quakes/sacfiles/961112/. In there you will find the 6 event files. That's it... Regards, Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Two files?? Date: Sat, 23 Nov 1996 22:49:04 -0700 Bob- With respect to your questions, > I might like to try to rec. some of the local telemetry data. Where can I > find frequencies and other details about telemetry around here? I suggest that you talk to Noel Barstowe at barstow@........................ or Paul Richards at Lamont. Good Luck! -Edward -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: SDR files & telemetry Date: 24 Nov 96 20:52:54 EST Larry, Thanks for all the good info on telemetry. Cranswick suggested a name at Lamont for frequencies, etc., in this area and I'm pursuing that. About my sending SDR files to the net: I sent the files to myself and that seems to be a mess--your files were decoded OK using DECODE64 but on my files it said "no name =" and quit. MIME64 did its job without complaint but PKUNZIP could not unzip them. This probably shows that you were right and that the problem is at my end. I have not yet compared the your SG and broadband recodings but I will. Sounds like a good experiment. My Lehman has been running with a 36 sec period for 6 days without any problem. I just removed the 0.08Hz LP filter to see how that goes. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David Alexander Subject: Re: SDR files & telemetry Date: Sun, 24 Nov 1996 19:58:28 -0800 (PST) On 24 Nov 1996, Robert L Barns wrote: ---snip--- > My Lehman has been running with a 36 sec period for 6 days without any > problem. I just removed the 0.08Hz LP filter to see how that goes. > Bob Barns > please excuse the ignorance. what is the period, how is it measured and how does it effect the measurements made by a unit? i have been following this group for sometime but i don't remember any discussion on the subject. tnx dave k7da _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: SDR files & telemetry Date: Sun, 24 Nov 1996 23:36:11 -0700 Hi Dave, The term period refers to the natural period that the pendulum, used in the sensor be it horizontal or vertical, swings at. This is usually measured with the damping removed so the pendulum will swing enough so you can measure it. For long period sensor you can use a stop-watch and measure the pendulum swing. A more hi-tech way is to record the signal from your sensor and then look at it with a program like WinQuake. For a sensor to be sensitive to other frequencies then the nature period, you must add damping. For the Lehman this is usually done with oil or magnetically with a copper or aluminum plate (copper works a lot better) between two magnets. For the SG sensor the damping is created electronically with a magnet on the pendulum and a coil mounted on the frame. The coil is driven by the position of the pendulum. Damping should not, or does not, change the period of the sensor. It only increase the sensitivity to other frequencies, and, at the same time decreasing the sensitivity to the natural period of the pendulum. From what I understand, and my knowledge about these things starts getting weak here, is as the damping increases the frequency response increase and the sensitivity decreases. At some point, as you increase the damping, the system becomes critically dampened. I think at this point the frequency response is the flattest. My guess is as you go past this point the sensitivity goes down without any frequency response increase. Is this correct? Can anyone elaborate on this? Regards, Larry Cochrane Redwood City, PSN At 07:58 PM 11/24/96 -0800, you wrote: > > >On 24 Nov 1996, Robert L Barns wrote: > >---snip--- > >> My Lehman has been running with a 36 sec period for 6 days without any >> problem. I just removed the 0.08Hz LP filter to see how that goes. >> Bob Barns >> > > >please excuse the ignorance. what is the period, how is it measured >and how does it effect the measurements made by a unit? > >i have been following this group for sometime but i don't remember >any discussion on the subject. > >tnx dave k7da > > > > > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Larry P. Thomas WA0GWA" Subject: Re: SDR files & telemetry Date: Mon, 25 Nov 1996 07:46:38 -0600 >>From what I understand, and my knowledge about these things starts getting >weak here, is as the damping increases the frequency response increase and >the sensitivity decreases. At some point, as you increase the damping, the >system becomes critically dampened. I think at this point the frequency >response is the flattest. My guess is as you go past this point the >sensitivity goes down without any frequency response increase. Is this >correct? Can anyone elaborate on this? > >Regards, >Larry Cochrane >Redwood City, PSN I've been a little confused in this area myself because I've been left with the impression that most people think they are lengthening the period of the pendulums electronically with dampening. I almost built an SG unit because I felt it was better for teleseismic measurements due to the longer period potential due to electronics. I'm now of the impression that it the sensor electronics of the SG that is more noise free for small magnitude events. The SG sensor is a position sensor as opposed to a velocity sensor as in the Lehman. I'm now in the process of building a Lehman mechanical system for the long period but plan to use the SG sensor. I also planning on applying all the good info recently that has come across on temperature, etc. Concerning critical dampening, these mechanical systems are no different than equivalent electrical systems and in them dampening has a real minor (if any) effect on resonance or period. A system has a "Q" or quality factor which controls the tendency to oscillate or swing at it natural resonance or mechanical period. Friction or resistance tends to take energy out of the system on each swing and the system dampens. Critical dampening is that amount of dampening which produces minimal over swing with return to nominal position with the least amount of friction. The Lehman can of course establish a longer natural period due to the large effective radius it swings through. Here are the ideas I'm applying to my sensor. I would like comments form anyone which an opinion. 1. Lehman mechanical system for long natural period. 2. Mechanical critical dampening using most likely oil (see #5 below) 3. No magnetic material of any kind on boom 4. Enclosed with heating as proposed in previous threads in SIG 5. SG type sensor (may or may not use the coil feedback for dampening) 6. I plan to modify SG sensor design a little by: a. not putting oscillator on boom and ... b. couple RF from oscillator to passive paddle on boom using small trough of mercury metal as a conductor to a probe from the plate which will keep any heat generators off the boom. 7. If I try the SG type coil dampening arrangement I'll also couple the signal to the coil via mercury pots for a non friction electrical coupling. Will put coil on boom and not magnet to avoid any magnetic material on boom. 8. Currently plan to use about 8Kg of lead at end of 2 foot fiber glass rod. Not decided yet are: 1. What type of pivots to use... Looking at knife edge for boom 2. Type of suspension element and it's method of pivot. Thanks for any comments Larry ----------------------------------------------------------------------- Larry P. Thomas wa0gwa voice : 1 913 888-0282 Krell Technologies fax : 1 913 782-9359 8960 Bond pager : 1 816 989-HELP Overland Park, KS 66214-1764 e-mail : lpthomas@................ ----------------------------------------------------------------------- _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Re: SDR files & telemetry Date: Mon, 25 Nov 1996 10:25:30 -0800 At 07:46 AM 11/25/96 -0600, Larry Thomas wrote: >I've been a little confused in this area myself because I've been left with >the impression that most people think they are lengthening the period of the >pendulums electronically with dampening. This is my understanding of how these things work. I would enjoy anyone else's comments / corrections as I am in the process of learning this stuff myself. You can in fact lengthen the period of these pendulums electronically, by doing more than just damping. Feedback systems can do damping (taking energy out of the pendulum) by exerting an opposing force (through the coil/magnet system) that is proportional to the speed of the movement. This is very much like the paddle moving in oil or a conductor moving in a magnetic field. Since this force acts through a distance, energy is taken out of the system and damping occurs. The SG system uses feedback which does damping, but also can be adjusted to provide some amount of positive feedback -- when the arm moves, it gives an additional push. This push isn't enough to keep it going to the stops, but just enough to oversome SOME of the gravity trying to restore it to the center position, effectively lengthening the period. This is an aiding force that is proportional to the position of the pendulum. About your ideas -- >3. No magnetic material of any kind on boom I like that idea. I've often thought that some of the noise seen could be from things like cars in the driveway, neighbor's driveway, on the street, etc. >2. Type of suspension element and it's method of pivot. Another good challenge to keep it non-magnetic. I'm working on essentially the same thing -- a Lehman mechanical system with a SG feedback to provide period lengthening and damping. -- Karl Cunningham karlc@......... La Mesa, CA. 116.9775W 32.7705N +308M interested in almost anything to do with science _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Larry P. Thomas WA0GWA" Subject: Re: SDR files & telemetry Date: Mon, 25 Nov 1996 13:53:43 -0600 At 10:25 AM 11/25/96 -0800, you wrote: >At 07:46 AM 11/25/96 -0600, Larry Thomas wrote: > >>I've been a little confused in this area myself because I've been left with >>the impression that most people think they are lengthening the period of the >>pendulums electronically with dampening. > >This is my understanding of how these things work. I would enjoy anyone >else's comments / corrections as I am in the process of learning this stuff >myself. > >You can in fact lengthen the period of these pendulums electronically, by >doing more than just damping. Feedback systems can do damping (taking >energy out of the pendulum) by exerting an opposing force (through the >coil/magnet system) that is proportional to the speed of the movement. >This is very much like the paddle moving in oil or a conductor moving in a >magnetic field. Since this force acts through a distance, energy is taken >out of the system and damping occurs. The SG system uses feedback which >does damping, but also can be adjusted to provide some amount of positive >feedback -- when the arm moves, it gives an additional push. This push >isn't enough to keep it going to the stops, but just enough to oversome >SOME of the gravity trying to restore it to the center position, >effectively lengthening the period. This is an aiding force that is >proportional to the position of the pendulum. Interesting explanation. I suppose if I had the time I could create a model for this system and do some analysis. I'm not sure how both dampening and period lengthening can both be at play in the situation >About your ideas -- > >>3. No magnetic material of any kind on boom > >I like that idea. I've often thought that some of the noise seen could be >from things like cars in the driveway, neighbor's driveway, on the street, >etc. > >>2. Type of suspension element and it's method of pivot. > >Another good challenge to keep it non-magnetic. > >I'm working on essentially the same thing -- a Lehman mechanical system >with a SG feedback to provide period lengthening and damping. Would like to be kept informed on your progress and results. ----------------------------------------------------------------------- Larry P. Thomas wa0gwa voice : 1 913 888-0282 Krell Technologies fax : 1 913 782-9359 8960 Bond pager : 1 816 989-HELP Overland Park, KS 66214-1764 e-mail : lpthomas@................ ----------------------------------------------------------------------- _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ct@....... (Charlie & Terri Thompson -- Buda MicroRanch ) Subject: Interesting URL on seismic electronics Date: Mon, 25 Nov 1996 21:56:05 -0600 Perhaps many of you know about this web page..however I thought it was interesting ...the page describes the University of Washington's seismic hardware and electronics. http://www.geophys.washington.edu/SEIS/PNSN/SHOP/shoppage.html Regards, Charlie Thompson Buda, Texas ct@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Roger Griggs Subject: What are normal signals on a Lehman Date: Thu, 28 Nov 1996 17:21:21 -0800 Hi Folks, I've been listening to the Lehman mail for some time and I would like to pose some questions to other seismograph stations that use a long period boom with Larry's SDR monitor and WinQuake. Unless you have seen other stations in person some may not know what to expect on the monitor readout showing general day to day signals. I see a very "lazy" 0.2 second signal that varies from 10 to 60 points peak to peak as shown on a save to WinQuake. Superimposed on that is a signal of maybe 16 cycles with a peak to peak of about 10. This 16 hz singnal is very stable at the 10 ppp but the 0.2 varies in cylces of about 18 seconds. I guess the questions are what is producing these signals and do others see the same thing. I would think the 0.2 sec wave is normal background noise. The 18 or so second variatin my be wind currents inside the enclosure. I don't know where the 16hz is coming from. Any answers out there? It is sensitive N to S and is under the house. It's sitting on a cement slab 1' by 2' by 6 ' deep on a sand base covered with a wood frame that is encased in fiberglass sheeting. I have the mating surfaces sealed with foam rubber door seal. It is very sensitive as I record 2.1M at 14km and 7.1 from Fuji. Just curious what others experience and if what I am seeing is normal. Roger end of line ... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: bfryer@............ (Bob Fryer) Subject: Re: Power of a Quake Date: Fri, 29 Nov 1996 13:36:44 -0800 (PST) Hello, Downloaded this item from somewhere on WWW: "Earthquakes with 1,000 or More Deaths from 1900" .... 1950 Aug 15 India, Assam, Tibet 28.7 N 96.6 E 1,530 8.7 Great topographical changes, landslides, floods.... You might try USGS or Seismo-Surfing. Bob Fryer On Fri, 22 Nov 1996 23:18:22 -0500, Tinkler@....... said: >Came across this discription of a earthquake in the magazine "The Watchtower >"that had happened back in 1950, in the region of the Himalayas. >In my book "An introduction to the theory of Seismology by K.E. Bullen" on >page 272 stated it had been given a magnitude of 8.7 by Mr. Richter and >Gutenberg, and is also mentioned in one of my Scientific America handbooks >dating back to 1957. >Does anybody else have any info on it. It amaze's me the power that would >have been generated that would be able to move 100's of millions of tons of >earth and rock straight up. > >*** w51 4/1 201-2 "Earthquakes in One Place After Another" *** >"Earthquakes in One Place After Another" >LAST August 15 the severest earthquake of the twentieth century, the "biggest >of the present generation", the "most drastic natural upheaval in a populated >place that the world ever has known", was centered in northeastern India, >Assam, Nepal and southern Tibet.... ----- earthquake WARNING research ----- --- http://www.teleport.com/~bfryer --- -- Animals, people, scientific evidence -- _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: RDJM@....... Subject: Magnitude scale Date: Fri, 29 Nov 1996 20:27:18 -0500 I read somewhere that the magnitude scale was related to the ground movement based on the following: movement(in micrometers) = 10 raised to the magnitude power (micrometers = 10^magnitude) at 100km distance from epicenter so that: magnitude 0 = 1 micrometer mag 1 = 10 micrometers mag 2 = 100 micrometers ........ mag 7 = 10,000,000 micrometers = 10 meters mag 8 = 100 meters Has anyone seen this reference? Since the Loma Prieta quake was about 100km away from the Bay area and was a mag 7+ did we move 10 meters? Seems like a lot especially when we are expecting a mag 8 (100 meters movement?????) anyday now in the area. Loma Prieta should have pegged all of the seismometers in the Bay area. Does anyone have data on local movements ( in meters or feet ) from this quake? The 1906 quake in San Francisco displaced fence lines that straddled the fault line by approx 7 meters (20 feet, I think) and was an 8+ so I guess the relationship could be possible. Any data? _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) Subject: Re: Magnitude scale Date: Fri, 29 Nov 1996 17:45:02 -0900 RDJM@....... writes: "movement(in micrometers) = 10 raised to the magnitude power (micrometers = 10^magnitude) at 100km distance from epicenter so that: magnitude 0 = 1 micrometer" You have the write idea, but the wrong numbers. The Richter magnitude is based on the formula: ML = log(A/Azero) where A is the measured zero to peak amplitude measured in mm on a Wood-Anderson photographic instrument and Azero is the predicted amplitude for a magnitude zero earthquake. Azero is, of course, a function of distance. The table given by Richter can be approximated, out to 200 km distance, by the formula log(azero) = 0.15 - 1.6 log(distance in km) log(azero) is approximately equal to minus 3 at 100 km, so azero is approximately equal to .001 mm at this distance. This is still not ground motion, however. If the frequency of the peak motion is well above the natural frequency (1.25 Hz) of the Wood-Anderson, then the magnification will be 2080 (see Urhammer and Collins, 1990, BSSA, v. 80, p. 702-716). This means that the ground motion for a magnitude zero earthquake measured 100 km away is mag 0 .001/2800 mm = .00036 microns mag 1 .0036 microns mag 2 .036 microns mag 3 .36 microns mag 4 3.6 microns .0036 mm mag 5 36 microns .036 mm mag 6 360 microns .36 mm mag 7 3,600 microns 3.6 mm JCLahr ################################# John C. Lahr ################################ U.S. Geological Survey ############################### c/o Geophysical Institute ############################## 903 Koyukuk Drive ########################################################### ########################################################### P.O. Box 757320 ################################ Fairbanks, AK 99775 ################################# Phone: (907) 474-7997 ################################## Fax: (907) 474-5618 ################################### lahr@........ #################################### _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: SDR files & telemetry Date: Sat, 30 Nov 1996 15:30:05 -0700 At 10:25 AM 11/25/96 -0800, Karl Cunningham wrote: >You can in fact lengthen the period of these pendulums electronically, by >doing more than just damping. Feedback systems can do damping (taking >energy out of the pendulum) by exerting an opposing force (through the >coil/magnet system) that is proportional to the speed of the movement. >This is very much like the paddle moving in oil or a conductor moving in a >magnetic field. Since this force acts through a distance, energy is taken >out of the system and damping occurs. The SG system uses feedback which >does damping, but also can be adjusted to provide some amount of positive >feedback -- when the arm moves, it gives an additional push. This push >isn't enough to keep it going to the stops, but just enough to oversome >SOME of the gravity trying to restore it to the center position, >effectively lengthening the period. This is an aiding force that is >proportional to the position of the pendulum. The SG sensors I am making do not have special damping that I know of. The SG sensor gets it low frequency response because it can detect the small horizontal, or tilting, of the pendulum as the waves go by. Because it measures displacement, the low frequency information is there in the signal but needs to be amplified using the integrator. The integrator compensates for the fact the pendulum becomes less sensitive as the frequency of the waves decrease. The way I look at it is (and I could be wrong here) the damping is only needed so the pendulum can measure displacement. Without it the pendulum would never settle down making it impossible to measure the small displacements needed to pick up teleseismic events. Now the problem I am having is trying to get a high frequency port out of the thing. Since the sensor is basically a short period horizontal system, one should be able to get higher frequency response that would be useful for local events. The sensors I am making have a very steep cut-off after the period of the pendulum, around 1-2 seconds. The first thing I tried was to record another channel right out of the summing amp. I was thinking that the integrator was filtering out the high freq info. This was not the case. After adding the new channel there was a local event and the FFT showed the sharp cut-off still there. The next thing I tried was increasing the damping. This helped a little but you can still see a sharp cut-off at the period of the pendulum. The next thing I will try is adding even more dampening. I still may not be at critical damping yet. The only other thing I can think of doing is add a magnet and coil to the system and get a real velocity signal out of the thing. Will see... A note about my Redwood City PSN site. During the testing of my SG sensor I am using my Lehman (*.LC1 files) channel for the second test port on my SG sensor. During my testing my Lehman will be off line. On a similar note, one of the telemetry channels I am monitoring, CMM (Mount Mocho) has a very low RF signal level so I moved this channel over to CNI. CNI is a sensor located around Niles Canyon. As soon as CMM is working again I will move it back. CNI is very close to the CGP site so it doesn't offer much input to locating events. Regards, Larry cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Re: SDR files & telemetry Date: Sun, 01 Dec 1996 09:02:26 -0800 At 03:30 PM 11/30/96 -0700, Larry Cochrane wrote: >The SG sensors I am making do not have special damping that I know of. The >SG sensor gets it low frequency response because it can detect the small >horizontal, or tilting, of the pendulum as the waves go by. Because it >measures displacement, the low frequency information is there in the signal >but needs to be amplified using the integrator. Larry -- You are absolutely right. I had looked at the schematics for the SG system a while back and thought I understood how they worked. Looking again, I was wrong. I appologize if I misled anyone. There doesn't seem to be any electronic period-lengthening involved. >Now the problem I am having is trying to get a high frequency port out of >the thing. Since the sensor is basically a short period horizontal system, >one should be able to get higher frequency response that would be useful for >local events. The sensors I am making have a very steep cut-off after the >period of the pendulum, around 1-2 seconds. The first thing I tried was to >record another channel right out of the summing amp. I was thinking that the >integrator was filtering out the high freq info. This was not the case. >After adding the new channel there was a local event and the FFT showed the >sharp cut-off still there. The next thing I tried was increasing the >damping. This helped a little but you can still see a sharp cut-off at the >period of the pendulum. The next thing I will try is adding even more >dampening. I still may not be at critical damping yet. The only other thing >I can think of doing is add a magnet and coil to the system and get a real >velocity signal out of the thing. Will see... Looking at the SG schematic, I think your cutoff might be caused by the damping system. Not because there is not enough, although that could be doing something too, but because of the frequency that the damping comes in. The two 100uF caps combined with the 3.3K resistor make the damping come in at 1Hz (by my calculations), which gives the system a 1Hz rolloff at the pendulum due to the damping. As a trial, you might decrease the value of the two caps. It should be inversely proportional to the cap value -- 10uF should give you 10Hz. You'll undoubtedly have to adjust the value of the "Note 2" resistor again. Let me know what happens. -- Karl Cunningham karlc@......... La Mesa, CA. 116.9775W 32.7705N +308M interested in almost anything to do with science _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jack Sandgathe Subject: Re: 12 bit A/D Date: Sun, 1 Dec 1996 20:49:00 -0800 (PST) Dear Ken, Thanks for letting us know about the following ADC system. I will contact the manufacturer about specs, and at the price, I expect it is a good deal. The only question I want to ask the group is whether it is compatible with Ted Blank's software and the files in use by the amateur crowd. Has anyone looked into this yet, or should I pass on whatever I can find out? Thanks for any feedback you can give, Jack Sandgathe At 07:54 AM 11/9/96 -0800, you wrote: > >Saw this on the newsgroups today. Just thought I'd pass it along. >Haven't heard of these guys before so... > >Ken. > >Newsgroups: sci.geo.earthquakes >Subject: $59 12-bit A/D for Seismometer >Date: Fri, 08 Nov 1996 22:54:38 -0600 >Organization: ADNAV Electronics >..... >A low-cost A/D that is well suited for the application has been >introduced by ADNAV Electronics. The LPT:Analog! v2.0 is a 12-bit >Analog-to-Digital adapter for the PC parallel printer port which sells >for US $59. >...... > For more information, please contact: > > ADNAV Electronics > 58 Chicory Ct. > Lake Jackson, TX 77566 > > (409)292-0988 > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Darrell Collins Subject: Re: 12 bit A/D Date: Mon, 2 Dec 1996 08:03:31 -0700 (MST) At 08:49 PM 12/1/96 -0800, you wrote: >Dear Ken, Thanks for letting us know about the following ADC system. AND > >At 07:54 AM 11/9/96 -0800, you wrote: >> >>Saw this on the newsgroups today. Just thought I'd pass it along. >>Haven't heard of these guys before so... >> Those of you looking for a low cost A-D converter for your system may wish to visit Radio-Sky Publishing, Louisville, KY at HTTP://www.win.net/~radiosky under the "A to D Circuit for Amateur Scientists" selection. The 12 bit circuit has to border on the least expensive (free) way to get up to 8 channels of data collection capability. And, he even has the parts available! Software is also there to make it all work. Be sure to check out the other software sections for low cost data logging and other useful items. This is an interesting, nicely done, and easy to use site. Darrell _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) Subject: Re: SDR files & telemetry Date: Mon, 2 Dec 1996 11:50:37 -0900 Larry Cochrane writes: "Now the problem I am having is trying to get a high frequency port out of the thing. Since the sensor is basically a short period horizontal system, one should be able to get higher frequency response that would be useful for local events." I plotted out below the basic shape, ignoring resonance, of the response one would get from pendulums fitted with distplacement and velocity transducers. Note that integration, while boosting the low frequencies, also reduces the high frequencies. To get the high frequency response you are used to from a velocity transducer, you would have to differentiate the output of the displacement tranducer. Of course that would cost you at the low frequency end! Seems there is no way around moving the natural frequency (fo) of the pendulum as close as possible to the lowest frequency of interest. JCLahr Magnification of pendulum with displacement transducer: | | *********** | * magnification | * | * +12 db/octive (f**2) | * _____________________________________ fo frequency, f Magnification of pendulum with displacement transducer, integrated once: | | * |+6db/o (f) * * -6db/octive (1/f) magnification | * * | * * | * * _____________________________________ fo frequency, f Magnification of pendulum with velocity transducer: | * | * | * +6db/octive (f) | * | * magnification | * | * +18 db/octive (f**3) | * _____________________________________ fo frequency, f _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Roger Sorensen Subject: Re: PSN Goodies !!! Date: Mon, 02 Dec 1996 15:04:41 -0800 The Public Seismic Network and Caliber Graphics join together to bring you the PSN goodies you have been waiting for: T-Shirts, Ball Caps, Bumper/Window graphics, and Desk Plaques Check out these items on the Pasadena PSN Web Page under the Store heading. (www.pacificnet.net/~darby) Caliber Graphics will make a donation to the PSN for each item sold. If you would like a text version of the Web Page, please e-mail me. If you have questions about these products, please call us at (818) 709-5117. Roger Sorensen (KD6LQE) - Caliber Graphics Roger.Sorensen@................ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Ken Navarre Subject: Re: 12 bit A/D Date: Mon, 2 Dec 1996 20:28:39 -0800 (PST) On Sun, 1 Dec 1996, Jack Sandgathe wrote: > Dear Ken, Thanks for letting us know about the following ADC system. I will > contact the manufacturer about specs, and at the price, I expect it is a > good deal. The only question I want to ask the group is whether it is > compatible with Ted Blank's software and the files in use by the amateur > crowd. Has anyone looked into this yet, or should I pass on whatever I can > find out? Thanks for any feedback you can give, Jack Sandgathe Jack (et al)... I have received the spiffy little LPT port A/D card and have a coupl'a observations. At $60 it's not bad but... 1) It's unipolar. In order to make it work we need to add a circuit to provide a voltage offset. No biggie but a problem that I neglected to anticipate. The documentation suggests a simple circuit powered by a 9 volt battery and offers a schematic. 2) It has a limited input voltage tolerance. 0 - 2.5 VDC is about all it'll handle. There is a sentence that advises that anything outside of -4 to +7 will ZAP the convertor. (Not quite their language but you get the point!) 3) Ted's EMON will not support it YET!!! I sent Ted a copy of the documentation to see if he can add it to the EMON.OPT option list. I'll let you know if is compatible and where to look for the revised EMON.EXE if and when it becomes available. More to follow! Ken _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: rond@................ (Charlie Rond) Subject: New Madrid Quake Date: Tue, 03 Dec 1996 02:08:18 -0600 Luckily, the turkey I stuffed was at midday, and having napped away its sedation, I was sitting quietly reading in a slumbering household when nature knocked at the door. My wife and I, and the dog, had driven from Memphis to her parents home in Steele, which lies a few miles into the Missouri bootheel - and astride the New Madrid seismic fault. With everyone else alseep, even the dog, an occasional passing car or a distant bark were the most significant sounds on Thanksgiving night. My immediate sensation was there had been a massive explosion, or a train wreck on the track several blocks away. As the house rocked back, I knew it was an earthquake. Like a giant fist on the door, it pounded several times and then quieted, leaving the floor "wallowing" and fluttering for a few more seconds. As unnerving as it was, I was glad to have survived it, but also excited and grateful to have been awake and intensely aware of the experience. I noted that it was 11:41pm cst, that in spite of its impact, nothing on the walls or shelves appeared disturbed, and that it had happened so suddenly I was still in my chair. I wondered if another "shoe would drop." My wife's father bounded into the room, wanting to know if a car had crashed into the house, and I realized that was a very apt description of the explosive impact. Then the others followed, including the dog, who sleeps through violent thunderstorms. I called the Center for Earthquake Research and Information (CERI) in Memphis and recorded a brief message about the event, then the Memphis newspaper to see if there had been other reports. A reporter said they were beginning to come in and called me back to ask my impressions. In the morning paper, I'd somehow become a resident, rather than a visitor, of Steele, MO, and was quoted as saying the quake felt like a "stroke explosion." I've never heard (nor used) that term, but I guess the reporter thought it sounded very "graphic." The quake was described as measuring about 4.3 with an epicenter west of Blytheville, Arkansas, about 10 miles southwest of Steele. It was followed about four hours later by one measuring just over 3.0, on the same fault system but across the Mississippi River in northwest Tennessee. There were no reported injuries from either event, and the only reported damage from the first quake was broken water pipes at a Tennessee prison. Though I've experienced several other tremors over the years in Memphis, which lies about 100 miles south of the New Madrid fault, this was the strongest I've felt, and the most significant since about 1991. The personal experience is a bitter/sweet compensation for missing the recording of it on my ailing seismograph. Though it's "old hat" to California veterans, and almost a puny event compared to many West Coast shakers, it has brought an awareness to the entire region not seen since the infamous - and false - prediction of 1990. The feature story on the local TV news program tonight was earthquake danger, preparedness and structural codes. The next time a 4+ rumbles along the San Andreas or Hayward, you'll have a more empathetic comrade sitting a little less comfortably just east of the Mississippi River. Charlie Rond -\/\--Public Seismic Network-Memphis rond@................ (901) 360-0302 [ free BBS ] http://gandlf.ceri.memphis.edu/~rond http://gandlf.ceri.memphis.edu/~rond/psn _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: mgray1@................ (Mike Gray) Subject: Re: New Madrid Quake Date: Tue, 03 Dec 1996 10:01:49 -0600 Glad you survived one, Charlie!!! May you survive many more! Let me rephrase that: May there not be many more, but if there are, may you survive them, too. In the early 60's, I lived in Dexter, Missouri and survived one that made cars bounce pretty high off the driveway and did alot of damage to structures. We were able to get to our feet, but were thrown down right after that. Merry Christmas and seasons greetings, all. Mike Gray MO Bureau of Emergency Medical Services (Dept of Health) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: rond@................ (Charlie Rond) Subject: Re: New Madrid Quake Date: Wed, 04 Dec 1996 00:29:35 -0600 Mike, >Glad you survived one, Charlie!!! May you survive many more! Let me >rephrase that: May there not be many more, but if there are, may you survive >them, too. Thanks very much for those sentiments, they are mine exactly! I'm really glad I was there and experienced it...and think I'd like to feel another one like that. But I don't WISH for any and I sure we hope we don't have any stronger that cause injury (or worse) and damage. >In the early 60's, I lived in Dexter, Missouri and survived one that made >cars bounce pretty high off the driveway and did alot of damage to >structures. We were able to get to our feet, but were thrown down right >after that. That was probably the ones I remember. The first I was driving to my parents on the Interstate and heard a boom which I thought was a truck beside me blowing a tire or something. When I got to my parents, they told me there had been an earthquake. As I was standing in the kitchen with them, the next one hit and I remember thinking the floor felt like it was on jello, wallowing underneath me to the extent I thought I might lost my balance. >Merry Christmas and seasons greetings, all. Merry Christmas and happy holiday wishes to you and yours up there in the shaky state. Charlie Rond -\/\--Public Seismic Network-Memphis rond@................ (901) 360-0302 [ free BBS ] http://gandlf.ceri.memphis.edu/~rond http://gandlf.ceri.memphis.edu/~rond/psn _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: George Bush Subject: Re: 12 bit A/D Date: Wed, 4 Dec 1996 14:22:58 -0800 (PST) Ken- You wrote: At 08:28 PM 12/2/96 -0800, you wrote: ....snip... >I have received the spiffy little LPT port A/D card and have a coupl'a >observations. At $60 it's not bad but... > >1) It's unipolar. In order to make it work we need to add a circuit to >provide a voltage offset. No biggie but a problem that I neglected to >anticipate. > Ken (or anyone else on the list), I would be interested in such a voltage offset circuit in reverse (unipolar to bipolar). I am building a three-axis seismometer based on the ADXL05 accelerometer. It's output is 0 to +5v and my A/D card input is -5 to +5 volts. any help would be appreciated. George _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: [Fwd: Re: "QuakeAlert" battery powered earthquake alarm system.] Date: Wed, 04 Dec 1996 19:08:50 -0700 -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". contiw wrote: > > Greeting, > > Tectonics Research Group Inc of St-Lambert, Quebec, Canada - phone > (514)4460948 claim that their QuakeAlert alarm system provide a useful > detection of P waves as precursors of S and R waves thus giving user > some precious time to react before their arrival. > > Does enybody know something about this? > > Regards. Walter Conti > contiw@.............. > Walter- It is very difficult to distinquish a P-wave produced by an earthquake from a local source of ground excitation, e.g., someone jumping on the ground next to the seismometer, using the data from only one seismometer. In special cases, such as during the aftershock sequence following the 1989 Loma Prieta earthquake, it is possible to use a locally recorded P-wave to predict the arrival of an S-wave at some more distant site. However, a device such as you describe above would not produce reliable warnings in general. -Edward -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". From: ct@....... (Charlie & Terri Thompson -- Buda MicroRanch ) Subject: Saw my first quake arrival tonight Date: Wed, 04 Dec 1996 22:29:06 -0600 Wow! I was sitting here on the telephone when I looked at my SDR program and saw my first realtime quake arrive here in Buda, Texas. It was interesting to watch how the waveform jumped around! Much higher frequency content than the usual background noise here in Texas. I uploaded the file to PSN if anyone cares to look. The quake was about 1000 miles from here....probably Mexico... we'll know for sure when the USGS identifies it. -Charlie Thompson Buda, Texas _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ct@....... (Charlie & Terri Thompson -- Buda MicroRanch ) Subject: Quake Identified Date: Wed, 04 Dec 1996 23:02:19 -0600 Well it's been about one hour since I last posted about seeing the quake arrive in real time. The USGS just identifed it as a Mag 5.3 Near Coast of Chiapas, Mexico. This is 1135 miles from Buda, Texas -Charlie _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: rond@................ (Charlie Rond) Subject: Re: Saw my first quake arrival tonight Date: Thu, 05 Dec 1996 01:10:22 -0600 >Wow! I was sitting here on the telephone when I looked >at my SDR program and saw my first realtime quake arrive >here in Buda, Texas. It was interesting to watch how the >waveform jumped around! Much higher frequency content than >the usual background noise here in Texas. I know how excited you are to see the real time signal arriving. There were two good examples of that for me. Once when a family friend came over and said she like to see the seismo. When we looked at it, the sine-wave type signals began growing in amplitude until they filled the screen. It was one of the Honshu events. The next was when my little nieces were visiting, wanted to see the computers, and only half believed me when I said they were watching the signal from a real quake. Keep up the good work. Charlie Rond -\/\--Public Seismic Network-Memphis rond@................ (901) 360-0302 [ free BBS ] http://gandlf.ceri.memphis.edu/~rond http://gandlf.ceri.memphis.edu/~rond/psn _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ct@....... (Charlie & Terri Thompson -- Buda MicroRanch ) Subject: Wave Identification Question -- (relayed message) Date: Thu, 05 Dec 1996 08:19:54 -0600 ---Note: I am posting this to the mailing list in hopes that others can help Bob as well -Charlie Thompson ------------------relayed message-------------------------- I am an Earth Science teacher in Midland, TX hopeflly about to get a seismograph at school. How did you learn to identify the waveforms on your records? Did you use a book or books and if so, might I have the reference(s)? I have not been able to find any local seismologists and I'd rather not bother the folks at TT in Lubbock to take their time to teach me. I'd appreciate any input you guys might have. Thanks, in advance Bob Avakian _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jeff Batten Subject: Saw my first real time quake roll in. Date: Wed, 04 Dec 1996 20:54:39 -0800 >Wow! I was sitting here on the telephone when I looked >at my SDR program and saw my first realtime quake arrive >here in Buda, Texas. It was interesting to watch how the >waveform jumped around! Much higher frequency content than >the usual background noise here in Texas. The most interesting real time quake I saw roll in was Northridge in 94. At 5 km from the epicenter it kind of threw the monitor off the desk it was sitting on, but it was recording for the first second, I saw the trace. After that the power failed, and for the next 15 seconds as I tried to stand up, I discovered what 1.5 horizontal g's felt like. Having studied earthquakes for many years, I knew that quakes can produce large accelerations. But I never imagined that the shaking could be so violent, I mean really violent. Scared the hell out of me, as the apartment started to disintegrate. I still cannot believe the apartment did not collapse. It was red tagged. Northridge meadows a few blocks away did. Thank God the quake occurred when it did, if it happened a few hours later, when the Northridge mall was open, and the freeways were moving, hundreds would have died. I hope never to be in another such quake, but living in S.Cal. I know it is only a matter of time. Now when I watch large distant quakes roll in on my home seismometer, I say a prayer and hope no one is dead or dying. Jeff Jeff Batten - Research Engineer Caltech Seismo Lab 818-395-6965 Fax-818-564-0715 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Cristiano Subject: Re: 12 bit A/D Date: Thu, 05 Dec 1996 11:20:42 -0700 George Bush wrote: > ...snip... > Ken (or anyone else on the list), I would be interested in such a > voltage offset circuit in reverse (unipolar to bipolar). I am building a > three-axis seismometer based on the ADXL05 accelerometer. It's output is 0 > to +5v and my A/D card input is -5 to +5 volts. any help would be appreciated. > > George George, Just take an op amp configured as a 10x amp and power it with the +/-5V from the A/D card. Input the signal from the ADXL50 into the inverting input resistor and then reference the non-inverting input resistor to the wiper of a potentiometer (~50K) that has one end to +5 volts and the other to ground. When the wiper is adjusted to match the voltage at the output of the ADXL50, the output of the op amp will be at 0 volts referenced to +/-5V. If the adjustment is too sensitive, use a 1-10K pot with 30K resistors on each end. Let me know if you need more info. Good luck. Jim Cristiano cristiano@........... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Leigh House" Subject: Re: Wave Identification Question -- (relayed message) Date: Thu, 5 Dec 1996 13:19:27 -0700 For Bob (and others?): You should probably try to get a copy of "Earthquake Interpretations: a Manual for Reading Seismograms", by Ruth Simon (then at Woodward-Clyde Consultants), published by William Kaufmann, Inc (One First St, Los Altos, CA 94022), 1981. This is a very nice compendium of interpretational tips, and example interpreted seismograms. There are several examples of deeper (depths of more than 60 km or so) earthquakes recorded at teleseismic distances, which show nice 'depth phases' (more formally called 'pP'). It also includes travel time charts for nearby earthquakes, and the Jeffreys-Bullen "Seismological Tables" for more distant earthquakes (which are summarized in the now-classic, and extremely helpful, J-B travel time curves, reproduced as Figure C in Simon's book). The maps of station locations (Figures A and B) and the discussion of instrumentation are, expectably, somewhat out of date. Nevertheless, the basic interpretational skills that are presented are still correct. I found a copy just by chance at a local bookstore several years ago; I don't know how easy it is to get now. Good Luck, Leigh House On Dec 5, 8:19am, Charlie & Terri Thompson -- Buda MicroRanch wrote: > Subject: Wave Identification Question -- (relayed message) > ---Note: I am posting this to the mailing list in hopes that others > can help Bob as well > > -Charlie Thompson > > ------------------relayed message-------------------------- > > I am an Earth Science teacher in Midland, TX hopeflly about to get a > seismograph at school. How did you learn to identify the waveforms on > your records? Did you use a book or books and if so, might I have the > reference(s)? I have not been able to find any local seismologists and > I'd rather not bother the folks at TT in Lubbock to take their time to > teach me. > > I'd appreciate any input you guys might have. > > Thanks, in advance > > Bob Avakian > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L >-- End of excerpt from Charlie & Terri Thompson -- Buda MicroRanch -- ------------------ Leigh House, Earth and Environmental Sciences Division MS D-443 Los Alamos National Laboratory Los Alamos, NM 87545 (email: house@......... Tel: 505-667-1912; FAX 505-667-8487) ------------------ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Saw my first real time quake roll in. Date: Thu, 05 Dec 1996 13:27:41 -0700 > After that the power failed, and for the next 15 seconds as I tried to stand > up, I discovered what 1.5 horizontal g's felt like. Having studied > earthquakes for many years, I knew that quakes can produce large > accelerations. But I never imagined that the shaking could be so violent, I > mean really violent. Scared the hell out of me, as the apartment started to > disintegrate. I still cannot believe the apartment did not collapse. It was > red tagged. Northridge meadows a few blocks away did. Thank God the quake > occurred when it did, if it happened a few hours later, when the Northridge > mall was open, and the freeways were moving, hundreds would have died. I > hope never to be in another such quake, but living in S.Cal. I know it is > only a matter of time. > > Now when I watch large distant quakes roll in on my home seismometer, I say > a prayer and hope no one is dead or dying. > > Jeff > Jeff Batten - Research Engineer > Caltech Seismo Lab > 818-395-6965 > Fax-818-564-0715 > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L Jeff- I liked your post about the Northridge EQ. We got there on Monday evening after the mainshock and therefore missed most of the fun. Of course, we got to Armenia two weeks after the mainshock, but they were still pulling the bodies out of the rubble then. That was not fun. -Edward -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Re: Saw my first real time quake roll in. Date: Thu, 05 Dec 1996 12:58:34 +0000 Jeff Batten wrote: > Now when I watch large distant quakes roll in on my home seismometer, I say > a prayer and hope no one is dead or dying. Truely a sobering concept. In so far as we scientist are amazed at the power of earthquakes, there is the flip side. Thousands of people people are killed by earthquakes each year. And yet, if you are outside, in an area not which has a minimual risk, to experience a strong earthquake is amazing. I remember the Morgan Hill 6.1 earthquake in 1984. I was working at a soils engineering lab in San Ramon, CA, when I felt the initial jolt. Realizing the S-waves were to follow shortly, I ran the back door of the tilt-up office complex to see the action. To my surprise, there was an ol' abandoned railroad track adjacent to the complex. I watched the seismic waves travel up the railroad grade, lifting the ground like waves in the ocean. The buildings began to shake, the cement loading tower about 100 yards away began to sway, and just as it seemed to increase in intensity, it stopped. A minor ripple followed a few seconds later. But the thrill of having my legs go up and down, surfing the seismic waves if you will, was...energizing. I was charged for days. Four years earlier, I road through the Eureka 7.2 earthquake. That was no party. It was violent! --- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: New Madrid Quake Date: Thu, 05 Dec 1996 14:22:10 -0700 Charlie- > The next time a 4+ rumbles along the San Andreas or Hayward, you'll have a > more empathetic comrade sitting a little less comfortably just east of the > Mississippi River. > As soon as I read this message last Tuesday night when I got back from Seattle, I forwarded the message to Mark Meremonte in this office who has been running some RefTek portable autonomous digital seismographs (PADS) in arrays at various locations near the Mississippi in Missouri and Tennessee. He was impressed by your account and in turn forwarded to various USGS people like Art Frankel and Chuck Mueller. Sorry I didn't let you know before. We should have some nice records of it. -Edward -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: bfryer@............ (Bob Fryer) Subject: Re: Saw my first real time quake roll in. Date: Thu, 5 Dec 1996 14:07:11 -0800 Jeff, >Now when I watch large distant quakes roll in on my home seismometer, I say >a prayer and hope no one is dead or dying. > >Jeff As a firefighter (retired) who has seen death and injuries many times, and experienced a few smaller quakes, I share your sentiments. Sunday, I will head to a conference in So. Carolina for a week, to better understand the people who "hear" the precursor signals from the Earth. Bob -- Beaverton, OR Charlie and Jeff said: >>Wow! I was sitting here on the telephone when I looked >>at my SDR program and saw my first realtime quake arrive >>here in Buda, Texas. It was interesting to watch how the >>waveform jumped around! Much higher frequency content than >>the usual background noise here in Texas. > >The most interesting real time quake I saw roll in was Northridge in 94. At >5 km from the epicenter it kind of threw the monitor off the desk it was >sitting on, but it was recording for the first second, I saw the trace. >After that the power failed, and for the next 15 seconds as I tried to stand >up, I discovered what 1.5 horizontal g's felt like. Having studied >earthquakes for many years, I knew that quakes can produce large >accelerations. But I never imagined that the shaking could be so violent, I >mean really violent. Scared the hell out of me, as the apartment started to >disintegrate. I still cannot believe the apartment did not collapse. It was >red tagged. Northridge meadows a few blocks away did. Thank God the quake >occurred when it did, if it happened a few hours later, when the Northridge >mall was open, and the freeways were moving, hundreds would have died. I >hope never to be in another such quake, but living in S.Cal. I know it is >only a matter of time. > >Now when I watch large distant quakes roll in on my home seismometer, I say >a prayer and hope no one is dead or dying. > >Jeff >Jeff Batten - Research Engineer >Caltech Seismo Lab >818-395-6965 >Fax-818-564-0715 > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L ----- earthquake WARNING research ----- --- http://www.teleport.com/~bfryer --- -- Animals, people, scientific evidence -- _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Cof2000@....... Subject: Earth Science Project Date: Thu, 5 Dec 1996 18:29:31 -0500 My question has to do with my ninth grade science project at Lexington High School in Lexington, Massachusetts. For the project, I have chosen to monitor siesmic activity around the Lexington area, as well as in Shaker Heights, Ohio, where my mother has family and I have access to another monitoring center. All I really want is some advice on how to build a good seismograph, or where I could buy a pre-made one for a fairly cheap price. I have already made an attempt at constructing a seismograph on my own, the results are less than satisfactory. I got a metal brace (a piece of metal bent at a 90 degree angle), and set it up like a hangman's hanger. I have a pencil attached to a weight attached to a spring hanging down from the brace. The problems are these: 1) I can't get the pencil to swing freely and press down on the paper hard enough to make a legitimate recording. 2) I don't know how to get a piece of paper to move at a consistent rate underneath the pencil. 3) If the pencil swings too much, it lifts off the paper and does not record. I hope anyone can help me. Thank you ahead of time. Brennan Igoe Cof2000@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: tblank@.......... (Ted Blank) Subject: Re: Wave Identification Question -- (relayed message) Date: Thu, 5 Dec 1996 22:05:42 -0800 (PST) For my money your best bet is to pick up a copy of Alan Jones' Seismic Waves Program. It shows actual recorded waveforms recorded at various distances from the epicenter, in real time, while you watch the waves travel across the surface of the earth and through a cross section of the earth all at the same time. If I hadn't seen it I wouln't have thought such a feat possible but Alan has pulled it off. Share ware $30 and free to schools. Grab it. > > ---Note: I am posting this to the mailing list in hopes that others > can help Bob as well > > -Charlie Thompson > > ------------------relayed message-------------------------- > > I am an Earth Science teacher in Midland, TX hopeflly about to get a > seismograph at school. How did you learn to identify the waveforms on > your records? Did you use a book or books and if so, might I have the > reference(s)? I have not been able to find any local seismologists and > I'd rather not bother the folks at TT in Lubbock to take their time to > teach me. > > I'd appreciate any input you guys might have. > > Thanks, in advance > > Bob Avakian > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Wave Identification Question -- (relayed message) Date: Thu, 05 Dec 1996 23:40:52 -0700 Ted Blank wrote: > > For my money your best bet is to pick up a copy of Alan Jones' Seismic > Waves Program. It shows actual recorded waveforms recorded at various > distances from the epicenter, in real time, while you watch the waves > travel across the surface of the earth and through a cross section of the > earth all at the same time. If I hadn't seen it I wouln't have thought > such a feat possible but Alan has pulled it off. Share ware $30 and free > to schools. Grab it. > > > > > ---Note: I am posting this to the mailing list in hopes that others > > can help Bob as well > > > > -Charlie Thompson > > > > ------------------relayed message-------------------------- > > > > I am an Earth Science teacher in Midland, TX hopeflly about to get a > > seismograph at school. How did you learn to identify the waveforms on > > your records? Did you use a book or books and if so, might I have the > > reference(s)? I have not been able to find any local seismologists and > > I'd rather not bother the folks at TT in Lubbock to take their time to > > teach me. > > > > I'd appreciate any input you guys might have. > > > > Thanks, in advance > > > > Bob Avakian > > > > > > _____________________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email listserver@............. with the body of the > > message: leave PSN-L > > > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L I think that is excellent advice because that is an excellent program for the purpose. I was going to suggest the same but you outpaced my procrastination. -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: rond@................ (Charlie Rond) Subject: Re: New Madrid Quake Date: Fri, 06 Dec 1996 00:47:40 -0600 Edward, >As soon as I read this message last Tuesday night when I got back from >Seattle, I forwarded the message to Mark Meremonte in this office who >has been running some RefTek portable autonomous digital seismographs >(PADS) in arrays at various locations near the Mississippi in Missouri >and Tennessee. He was impressed by your account and in turn forwarded >to various USGS people like Art Frankel and Chuck Mueller. Sorry I >didn't let you know before. We should have some nice records of it. Thanks for sending it on, and thanks for the feedback. Give my regards to Mark when you talk to him next. Hope one day we'll get to forage a bit. Can those records be translated to a format viewable by Winquake or QuakeVU? Regardless, I'd like to get a nice paper copy of one of the seismograms - especially since I didn't. Charlie Rond -\/\--Public Seismic Network-Memphis rond@................ (901) 360-0302 [ free BBS ] http://gandlf.ceri.memphis.edu/~rond http://gandlf.ceri.memphis.edu/~rond/psn _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: BZIMMERMAN@............ Subject: Re: Wave Identification Question -- (relayed message) Date: Fri, 06 Dec 1996 09:12:34 -0500 (EST) Where can I get a copy of Alan Jones' Seismic Waves Program ? _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: mgray1@................ (Mike Gray) Subject: Re: Saw my first real time quake roll in. Date: Fri, 06 Dec 1996 09:30:55 -0600 >As a firefighter (retired) who has seen death and injuries many times, and >experienced a few smaller quakes, I share your sentiments. Sunday, I will >head to a conference in So. Carolina for a week, to better understand the >people who "hear" the precursor signals from the Earth. > >Bob -- Beaverton, OR Bob, will other types of possible precursors be discussed? I am interested in those related to electromagnetic phenomena, specifically apparent frequency shifts. If you could keep an ear and eye out for that and report back (get copies of handouts), I would appreciate it. Thanks. Mike Gray MO Bureau of Emergency Medical Services (Dept of Health) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert Mathieson Subject: Re: Wave Identification Question -- (relayed message) Date: Fri, 6 Dec 1996 08:39:58 -0600 (CST) At 09:12 AM 12/6/96 -0500, you wrote: > >Where can I get a copy of Alan Jones' Seismic Waves Program ? > >_____________________________________________________________________ > > Me too! Robert Mathieson Culver-Stockton College Canton, MO 63435 (217)233-6000 rmathieson@.......... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Cristiano Subject: Re: Earth Science Project Date: Fri, 06 Dec 1996 07:57:29 -0700 Cof2000@....... wrote: > > My question has to do with my ninth grade science project at Lexington High > School in Lexington, Massachusetts. > All I really want is some advice on how to build a good > seismograph, or where I could buy a pre-made one for a fairly cheap price. > The problems are these: 1) I can't get the pencil to swing freely and press > down on the paper hard enough to make a legitimate recording. 2) I don't > know how to get a piece of paper to move at a consistent rate underneath the > pencil. 3) If the pencil swings too much, it lifts off the paper and does > not record. I hope anyone can help me. Thank you ahead of time. > > Brennan Igoe > Cof2000@....... Brennan, Yeah, thats how the text books show how a seismometer works but if you've been monitering this mail list you can see that it's a whole different story. I'm supprised you haven't gotten 400 replies by now. Information on building low cost seismometers is right here at the psn.quake web page. Since you are a teacher at a high school, you might check out the about PEPP (Princeton Earth Physics Project) info button at lasker.princeton.edu/pepp.shtml . They will provide equipment and info to set up a seismic monitering station at the high school. By the way, does anyone have info on how the PEPP seismos work? From what I could gather, they have two different types. Sensor construction would be interesting. Jim Cristiano cristiano@........... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Magic number for SDR Date: 06 Dec 96 14:26:59 EST Hi gang, Here's a magic number for Cochrane's beautiful SDR prog. Sometines I find it useful to many hours or even a whole 24 hrs. of a CHANx.yyy file. In REPLAY, I set Y Scale = 20 (or whatever pops your cork) and X Scale = 141 and 8 lines (or any even no. of lines). The 141 is the magic number in that this makes one line 30 mins. (rather accurately) and you get 4 hrs. (with 8 lines) on one screen. If you give a starting time of Xhrs 0mins 0secs, it is easy to read the time of any interesting feature. [The theory is: 50(samp/sec) *60(secs/min)*30(mins) / 141 = 638 and the X-axis is 640 pixels wide. So the error is a measly 0.3%] Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Wave Identification Question -- (relayed message) Here are Allan Jones prog Date: Fri, 06 Dec 1996 13:00:10 -0700 Alan Jones programs can be obtained at: http://www.geol.binghamton.edu/faculty/jones/jones.html -Edward Robert Mathieson wrote: > > At 09:12 AM 12/6/96 -0500, you wrote: > > > >Where can I get a copy of Alan Jones' Seismic Waves Program ? > > > >_____________________________________________________________________ > > > > > > Me too! > > Robert Mathieson > Culver-Stockton College > Canton, MO 63435 > (217)233-6000 > rmathieson@.......... > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: Wave Identification Question -- (relayed message) Date: Sat, 07 Dec 1996 09:37:57 +1200 At 09:12 AM 12/6/96 -0500, you wrote: > >Where can I get a copy of Alan Jones' Seismic Waves Program ? > check the bottom of my quake home page there are several click and go to software locations including seismic waves and seis/volc. the end of this message has my PSN home page loc. Dave Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm ( world wide access ) http:/www.es.co.nz/~dann/home.html ( New Zealand access only ) SOD'SLAW-- When Something Does Go Wrong, There Is Sod All You Can Do AboutIt When The Last Of Ten Screws Has Been Removed From A Cover, It Will Be Discovered That The Wrong Cover Has Been Removed When The Last Of Ten Screws Has Been fitted back Into A Cover, It Will Be Discovered That The gasket Has Been Left Out _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Steve Hammond Subject: Re: Wave Identification Question -- (relayed message) Date: Fri, 6 Dec 1996 13:44:08 -0800 (PST) I got involved with this same question presented by a fellow in France. I also suggested EI by Ruth Simon's and in trying to find a seller talked to William Kaufmann. He told me that it is out of print and thaty it was ok to go to the local copier and reproduce a copy for the fellow... Regards, Steve hammond PSN BBS San Jose 408-226-0675 On Thu, 5 Dec 1996, Leigh House wrote: > For Bob (and others?): > > You should probably try to get a copy of "Earthquake Interpretations: a > Manual for Reading Seismograms", by Ruth Simon (then at Woodward-Clyde > Consultants), published by William Kaufmann, Inc (One First St, Los > Altos, CA 94022), 1981. This is a very nice compendium of > interpretational tips, and example interpreted seismograms. There are > several examples of deeper (depths of more than 60 km or so) > earthquakes recorded at teleseismic distances, which show nice 'depth > phases' (more formally called 'pP'). It also includes travel time > charts for nearby earthquakes, and the Jeffreys-Bullen "Seismological > Tables" for more distant earthquakes (which are summarized in the > now-classic, and extremely helpful, J-B travel time curves, reproduced > as Figure C in Simon's book). > > The maps of station locations (Figures A and B) and the discussion of > instrumentation are, expectably, somewhat out of date. Nevertheless, > the basic interpretational skills that are presented are still correct. > > I found a copy just by chance at a local bookstore several years ago; I > don't know how easy it is to get now. > > Good Luck, > Leigh House > > On Dec 5, 8:19am, Charlie & Terri Thompson -- Buda MicroRanch wrote: > > Subject: Wave Identification Question -- (relayed message) > > ---Note: I am posting this to the mailing list in hopes that others > > can help Bob as well > > > > -Charlie Thompson > > > > ------------------relayed message-------------------------- > > > > I am an Earth Science teacher in Midland, TX hopeflly about to get a > > seismograph at school. How did you learn to identify the waveforms > on > > your records? Did you use a book or books and if so, might I have > the > > reference(s)? I have not been able to find any local seismologists > and > > I'd rather not bother the folks at TT in Lubbock to take their time > to > > teach me. > > > > I'd appreciate any input you guys might have. > > > > Thanks, in advance > > > > Bob Avakian > > > > > > _____________________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email listserver@............. with the body of > the > > message: leave PSN-L > >-- End of excerpt from Charlie & Terri Thompson -- Buda MicroRanch > > > > -- > > ------------------ > Leigh House, Earth and Environmental Sciences Division > MS D-443 > Los Alamos National Laboratory > Los Alamos, NM 87545 > > (email: house@......... Tel: 505-667-1912; FAX 505-667-8487) > ------------------ > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: please help LP seismom. Date: Sat, 07 Dec 1996 09:47:22 +1200 hey all you professionals out there, I have a Sprengnether long period horizontal seismometer that I would like to know how to apply the appropriate dampening to it. For those of you who don't know the " beast " too well, it is a very heavy, has a triangular shaped base (~2 feet per side), has 3 coils and 2 magnets. The 2 main coils are ~500 ohms each and can be used for signal out to recording gear.... the 3rd a smaller coil ~ 200 ohms possibly has some sort of feedback signal fed into it for the dampening ????? the principal of operation is basically the same as the Lehman ie a horiz. swinging pendulum with magnet and coil. I have a small booklet describing the assembly and how to change the period but nothing about the dampening. thoughts and advice appreciated thanks Dave Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm ( world wide access ) http:/www.es.co.nz/~dann/home.html ( New Zealand access only ) SOD'SLAW-- When Something Does Go Wrong, There Is Sod All You Can Do AboutIt When The Last Of Ten Screws Has Been Removed From A Cover, It Will Be Discovered That The Wrong Cover Has Been Removed When The Last Of Ten Screws Has Been fitted back Into A Cover, It Will Be Discovered That The gasket Has Been Left Out _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: the PSN down under Date: Sun, 08 Dec 1996 19:25:00 +1200 hi all, well the PSN has now truely infiltrated the southern hemisphere with the successful building and installation of the first of several of Larry's SDR systems in New Zealand. It will compliment the continued use of the ' good old ' standard rotating drum and ink pen system. I have a soft spot for the pen recorder and it will continue in use as a single channel short period system. The SDR sys. has at present a short period vert. seismom. on it and when I can sort out how to dampen that USA built " Sprengnether' L.P. unit, it will be added as a second channel. For those of you who are interested in solar activity as well, I intend to use another of the channels as a solar flare recorder by taking the audio out of a receiver at 30 MHz (10m). The SDR will record the increase in the audio voltage level that develops across the radio speaker during the flare. Events posted to Larry's web site for downloading will have the file name ending in .DND which is a standard abbrev. for Dunedin city where I live. cheers all Dave Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm ( world wide access ) http:/www.es.co.nz/~dann/home.html ( New Zealand access only ) SOD'SLAW-- When Something Does Go Wrong, There Is Sod All You Can Do AboutIt When The Last Of Ten Screws Has Been Removed From A Cover, It Will Be Discovered That The Wrong Cover Has Been Removed When The Last Of Ten Screws Has Been fitted back Into A Cover, It Will Be Discovered That The gasket Has Been Left Out _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Darrell Collins Subject: Re: Earth Science Project Date: Mon, 9 Dec 1996 08:44:33 -0700 (MST) > > By the way, does anyone have info on how the PEPP seismos work? From what > I could gather, they have two different types. Sensor construction would > be interesting. > > Jim Cristiano cristiano@........... > Jim, In a discussion I had with Terry Wallace at U of Ariz last summer, he stated that there were two types under evaluation for the PePP program. (Designs based on a response to an RFP to produce a device that ...... and cost < $1500.) He said that the most promising was based on an electrolytic transducer, a sort of sensitive, U-tube, Tilt meter. I can understand how such a device would work in the Horiz axis, but have difficulties visualizing the Vert axis???? The other was based on the accelerometer design similar to the Scientific American article. At that time neither system had passed all the acceptance test, and, as a result none had been delivered to any school. Great optimism to get a system up before the year end :) I,too, would like to see what the inards of these devices looked like. Darrell _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Dennis Leatart Subject: Local Quake Date: Mon, 09 Dec 1996 13:22:06 -0800 Hi to All! I am new at this so please bare with me!!! I have just picked up an event at 21:10 UT-- appears to be a local quake. I am at 118.19W and 34.3N in Moorpark, CA near L.A. Did anyone else get this? It was short about two minutes long. I am using a RANGER vertical seismometer. -- _____ __ | \.-----.-----.-----.|__|.-----. | -- | -__| | || ||__ --| |_____/|_____|__|__|__|__||__||_____| _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: Local Quake Date: Tue, 10 Dec 1996 10:55:40 +1200 At 01:22 PM 12/9/96 -0800, you wrote: >Hi to All! > >I am new at this so please bare with me!!! I have just picked up an >event at 21:10 UT-- appears to be a local quake. I am at 118.19W and >34.3N in Moorpark, CA near L.A. Did anyone else get this? It was short >about two minutes long. I am using a RANGER vertical seismometer. GREETINGS, you didn't sign your message so I don't know your name, for possible confirmation check Larry Cochranes' web pages http:/psn.quake.net the quake event files that he records are updated every 5 minutes or so. If it was too small/far away for him to record, try the Southern California Earthquake Centre (SCEC) they may have the info :: http://www.scecdc.scec.org/ happy shaking Dave Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm ( world wide access ) http:/www.es.co.nz/~dann/home.html ( New Zealand access only ) SOD'SLAW-- When Something Does Go Wrong, There Is Sod All You Can Do AboutIt When The Last Of Ten Screws Has Been Removed From A Cover, It Will Be Discovered That The Wrong Cover Has Been Removed When The Last Of Ten Screws Has Been fitted back Into A Cover, It Will Be Discovered That The gasket Has Been Left Out _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Tis the Season to be Seismic, trah, lah, lah, lah ... bang, boom, roll Date: Tue, 10 Dec 1996 01:33:04 -0700 Larry- When I saw those lights on the Redwood City PSN homepage, I figured you should think about bagging it and becoming Santa Seismo Claus, the bringer of good vibes! We are all getting close to critical! Merry Whatever! -Edward -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: Re: Tis the Season to be Seismic, trah, lah, lah, lah ... Date: Tue, 10 Dec 1996 22:22:00 +1200 At 01:33 AM 12/10/96 -0700, you wrote: >Larry- >When I saw those lights on the Redwood City PSN homepage, I figured >you should think about bagging it and becoming Santa Seismo Claus, >the bringer of good vibes! We are all getting close to critical! >Merry Whatever! >-Edward > Hear, Hear !! I second that motion, critical is almost an understatement.... I've had my SDR recorder going for a week now and am still waiting for a b***dy quake to give it its' first good trial. We need a few good M7 ++ events in unpopulated regions somewhere (middle of the ocean) to get the seismo's working. Dave Dave A. Nelson 24 Jensen St., Green Is., Dunedin, South Is.. New Zealand. http://psn.quake.net/dave/home.htm ( world wide access ) http:/www.es.co.nz/~dann/home.html ( New Zealand access only ) SOD'SLAW-- When Something Does Go Wrong, There Is Sod All You Can Do AboutIt When The Last Of Ten Screws Has Been Removed From A Cover, It Will Be Discovered That The Wrong Cover Has Been Removed When The Last Of Ten Screws Has Been fitted back Into A Cover, It Will Be Discovered That The gasket Has Been Left Out _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@................. (Dr. John Lahr (USGS-GI Seismologist)) Subject: Computed Arrival Times Date: Tue, 10 Dec 1996 20:44:24 -0900 I'm running a "home" seismograph and found that the triggering with just one stations is not sensitive enough to catch most earthquakes. Lowering the threshold or recording continuously creates a lot of data to look through for possible earthquakes. To make this easier, I've set up a web page that allows one to enter their station coordinates and their choice of finger server. Then the computed arrival times of body phases at their station are computed, based on the IASPEI91 Earth model and subroutines from Ray Buland and Arthur Snoke. This should make it possible to more quickly find arrivals at your seismic station among a large set of triggers. The minimum magnitude and maximum distance of interest can be set to eliminate events that would not likely be recorded. This is Beta Version 0.0, so expect problems! So, please give me feedback and let me know if it's helpful. I'll be in the Bay Area from December 14 through January 4, so will not be able to make changes for a few weeks. The URL is: http://www.giseis.alaska.edu/Input/lahr/artim.html JCLahr ################################# John C. Lahr ################################ U.S. Geological Survey ############################### c/o Geophysical Institute ############################## 903 Koyukuk Drive ########################################################### ########################################################### P.O. Box 757320 ################################ Fairbanks, AK 99775 ################################# Phone: (907) 474-7997 ################################## Fax: (907) 474-5618 ################################### lahr@........ #################################### _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Ben Grace Subject: Re: Local Quake Date: Wed, 11 Dec 1996 00:13:27 -0800 Dennis Leatart wrote: > > Hi to All! > > I am new at this so please bare with me!!! I have just picked up an > event at 21:10 UT-- appears to be a local quake. I am at 118.19W and > 34.3N in Moorpark, CA near L.A. Did anyone else get this? It was short > about two minutes long. I am using a RANGER vertical seismometer. > -- > _____ __ > | \.-----.-----.-----.|__|.-----. > | -- | -__| | || ||__ --| > |_____/|_____|__|__|__|__||__||_____| > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L --------------------------------------------------------------------- Dennis, I was interested in the RANGER seismometer you mentioned. Where would I look for more info on it? I am still learning about these things and your the first one I have heard about this from. Thank you, Ben Grace, wa7bef P.O.Box 138 Clancy, MT 59634-0138 Ph: 406-933-5646 e-mail: wa7bef@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Computed Arrival Times Date: Wed, 11 Dec 1996 13:07:14 -0700 John- I am impressed by your web-based travel time calculator. Since harddrives are cheap now, alot of PSN stations can follow Larry Cochrane's lead and record continuously, effectively maintaining a buffer that always has the last several days of record on line. Then they can use your calculator to automatically (manually, at least until someone comes up with the necessary nifty code) to extract a time window that starts prior to the first arrival and contains whatever phases that might be available. We plan to do that with the cellular-phone-equipped RefTek portable autonomous digital seismograph (PADS) that we have set up in Seattle, WA, for site-response studies, http://geohazards.cr.usgs.gov/engnseis/chase_eq.html , once sharper minds than mine have worked out some cell-phone telemetry difficulties. Regret that I won't be at AGU in San Francisco and have a chance to talk to you. Good luck in the digital maelstrom. -Edward -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Dennis Leatart Subject: Re: Computed Arrival Times Date: Wed, 11 Dec 1996 17:37:26 -0800 Dear Ben Grace: Hi!! The instrument you speak of is an older model RANGER that was donated by the seismo labs at Caltech to my school. So, I probably know little about it myself other than it seems to work great. -- _____ __ | \.-----.-----.-----.|__|.-----. | -- | -__| | || ||__ --| |_____/|_____|__|__|__|__||__||_____| _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ACole65464@....... Subject: Re: Computed Arrival Times Date: Wed, 11 Dec 1996 22:32:59 -0500 Dennis and Ben, I have some info about this seismometer on a single page brochure from Kinemetrics that describes their "SS-1" model Ranger. It is a 1 sec nominal, adj from .5 to 2 seconds, period velocity seismometer, stationary coil, magnet is the suspended mass. It has a seperate calibration coil. Can be adjusted for either horizontal or vertical motion. It appears that it is a very good quality instrument, if it has been well maintained. Allan Coleman _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Ben Grace Subject: Re: Computed Arrival Times Date: Wed, 11 Dec 1996 23:58:35 -0800 ACole65464@....... wrote: > > Dennis and Ben, > I have some info about this seismometer on a single page brochure from > Kinemetrics that describes their "SS-1" model Ranger. It is a 1 sec nominal, > adj from .5 to 2 seconds, period velocity seismometer, stationary coil, > magnet is the suspended mass. It has a seperate calibration coil. Can be > adjusted for either horizontal or vertical motion. It appears that it is a > very good quality instrument, if it has been well maintained. > Allan Coleman > > _____________________________________________________________________ Allen, Yes I am interested in your reply. Is it possible to photocopy any information you can and send to me? I will gladly pay for the photocopies, mail etc. Thank you Ben Grace, wa7bef@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Ben Grace Subject: Re: Computed Arrival Times Date: Thu, 12 Dec 1996 00:02:25 -0800 Dennis Leatart wrote: > > Dear Ben Grace: > > Hi!! The instrument you speak of is an older model RANGER that was > donated by the seismo labs at Caltech to my school. So, I probably know > little about it myself other than it seems to work great. > -- > _____ __ > | \.-----.-----.-----.|__|.-----. > | -- | -__| | || ||__ --| > |_____/|_____|__|__|__|__||__||_____| > > _____________________________________________________________________ Dennis, Thanks for the reply. Would it be possible to get photocopies of anything you can send concerning this device? I would gladly pay for the photocopies, mail, etc. Thank You Ben Grace, wa7bef@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Phil Giannini" Subject: AGU Date: 12 Dec 1996 07:39:00 U REGARDING AGU Hi Fellow Enthusiasts, What is this "AGU" thing I've been hearing about that is suppose to take place in San Francisco? Where in San Francisco is this going to be? Is it something I should attend? Can I attend it? In other words does any body have any information about it. Seeing how I live in San Francisco and am always interested in learning something new about earthquakes I thought this might be a chance to get enlightened. Any Info will be appreciated. Thanks, Phil (SFN SFZ) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: bob@................. (Bob Hammond (USGS-AVO Geophysicist)) Subject: Kinemetrics SS-1 Ranger seismometer Date: Thu, 12 Dec 1996 07:37:30 -0900 The Ranger is a good seismometer. The only failing I'm aware of is that the o-ring at the base of the cover (long aluminum tube extending out of the top of the instrument) tends to leak allowing water into the case. And ruining the seismometer. This seismo or a variation of it was left on the moon as part of the Apollo Program, I think. regards to all, Bob Hammond, APSN, Fairbankie Tanango, AK "send daylight: we're fresh out!" _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: AGU Date: Thu, 12 Dec 1996 13:24:35 -0700 Phil- "AGU" refers to the annual meeting of the American Geophysical Union which is to be held in San Francisco 12/15-12/19. It is one of the biggest professional meetings for seismology as well as for other geophysical disciplines. It costs several hundred dollars to attend, with some discount for members. More information is available at the website below: http://www.agu.org/meetings/fm96top.html Good luck! -Edward Phil Giannini wrote: > > REGARDING AGU > > Hi Fellow Enthusiasts, > What is this "AGU" thing I've been hearing about that is suppose to take > place in San Francisco? Where in San Francisco is this going to be? Is it > something I should attend? Can I attend it? In other words does any body have > any information about it. > Seeing how I live in San Francisco and am always interested in learning > something new about earthquakes I thought this might be a chance to get > enlightened. Any Info will be appreciated. > > Thanks, Phil (SFN SFZ) > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: tblank@.......... (Ted Blank) Subject: Re: Kinemetrics SS-1 Ranger seismometer Date: Thu, 12 Dec 1996 22:51:42 -0800 (PST) Oh no! And they just discovered water on the moon! Well, guess I'll have to volunteer to head on up and replace that o-ring... Ted Blank > > > The Ranger is a good seismometer. The only failing I'm aware of is that the o-ring at the > base of the cover (long aluminum tube extending out of the top of the instrument) > tends to leak allowing water into the case. And ruining the seismometer. > > This seismo or a variation of it was left on the moon as part of the Apollo Program, I think. > > regards to all, > > Bob Hammond, APSN, Fairbankie Tanango, AK > > "send daylight: we're fresh out!" > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: BASIC prog. to predict P, S & LQ times Date: 13 Dec 96 10:51:15 EST Hi gang, Some traffic recently about predicting the arrival times of various phases given lat & lon of both locations and the origin time prompts me to send in my BASIC prog. for this. It is attached in ASCII. I found the heart of the prog. somewhere [advice to programmers:plagarize! Tom Lehrer had it right.]. The neat stuff in the prog. is the borrowed part and the rest is in my usual helter-skelter style. It runs in GWBASIC so will probably run in any BASIC. You should substitute your lat and lon in lines 225, 245 and change line 268. Line 415 embodies a neat recipe for the radius of the earth discovered by a friend, John Sheetz. Rather than incorporate long tables for times vs dist., I derived equations by least squares fitting to the JB tables for a depth of 33. The fits were essentially perfect. The prog. will output arrival times even for those distances beyond the limits of the tables so take these with a grain of salt. The azi is the angle from you to the quake. I find this easier to use than the angle from the quake. I suspect that the prog. will fail for very short distances. I use this prog. as follows:From the quake reports on this net, I get the org., lat & lon. Then the dist., azi and arrival times are gotten from the prog. Then I know exactly where to look in the BIIG SDR files. Bob Barns Berkeley Hts., NJ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: GeoMonitr@....... Subject: Re: AGU Date: Fri, 13 Dec 1996 10:58:41 -0500 AGU stands for the American Geophysical Union, a professional group that has it's convention - - not sure of the time, but I think it's this week. Vince _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Re: please help LP seismom. Date: 13 Dec 96 10:51:13 EST Dave Nelson, About your question on the Sprengnether LP seis.:I have no knowledge of this item so the following is pure guesswork, beware! I'm guessing that the smaller coil is a calibration facility--a known current for a known time might produce a known acceleration of the pend. Try a resistor, say 100 ohms, across one of the 500 ohm coils to produce damping. A lower resistor value will increase the damping. That will reduce the signal level or you could use the other 500 ohm coil for signal. Since most of our seismometers are velocity devices, it is necessary to integrate the output to determine when critical damping has been achieved. I found that using a microscope of 10X-40X power (stereo is best) and an eyepiece with a scale (or just a mark) to observe the motion of the pendulum is the easiest way to observe and adjust the damping. What is the model no. of the Sprengnether and what is its period? It would be helpful if people on this net would report details of commercial instruments. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: George Bush Subject: Re: please help LP seismom. Date: Fri, 13 Dec 1996 14:20:46 -0800 (PST) Bob Barns wrote: >It would be helpful if people on this net would report details of commercial >instruments. Yes, I agree, and was just about to make the same request myself. I have a fine old surplus seismometer that really works great, but I would like to know more about it. I hope some people on this net can help me with any information on a seismometer made by: Geotechnical Corp. Garland Texas Model 8700C Serial 70 I have done a net search (both on Geotechnical and Garland TX), and have turned up nothing. I am curious what all the connectors were for, and how to adjust and maintain it. Any help would be appreciated. George _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ct@....... (Charlie & Terri Thompson -- Buda MicroRanch ) Subject: Geotechnical Corp Date: Fri, 13 Dec 1996 16:44:03 -0600 You might try the Thomas Register to find a mailing address for the Geotechnical Corp. Do a Yahoo search on "Thomas Register" to get their URL. The Thomas Register is a great on-line listing of almost ALL companies in the USA. -Charlie (BUE) >Bob Barns wrote: > >>It would be helpful if people on this net would report details of >commercial >instruments. > >Yes, I agree, and was just about to make the same request myself. I have a >fine old surplus seismometer that really works great, but I would like to >know more about it. I hope some people on this net can help me with any >information on a seismometer made by: > > Geotechnical Corp. > Garland Texas > Model 8700C > Serial 70 > >I have done a net search (both on Geotechnical and Garland TX), and have >turned up nothing. I am curious what all the connectors were for, and how to >adjust and maintain it. Any help would be appreciated. > >George > > > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: bob@................. (Bob Hammond (USGS-AVO Geophysicist)) Subject: Re: Geotechnical Corp Date: Fri, 13 Dec 1996 14:08:40 -0900 The Geotechnical Corp. was renamed to Teledyne Geotech and is now called Teledyne Brown Engineering. It is located in Garland, TX and the phone number is 214-343-7626. Their seismic instruments webpage is at www.tbe.com/products/instrument.html hope this helps. Bob Hammond, APSN, Fairbanks,AK _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Computed Arrival Times Date: Fri, 13 Dec 1996 16:54:37 -0700 John- How did make the calculator? with Java? -Edward -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: shansen@........ (shansen) Subject: Update on the Microbarograph Date: Fri, 13 Dec 1996 21:16:00 -0500 (EST) Back in July or thereabouts I'd posted several notes on the microbarograph that I was constructing for the purpose of monitoring infrasonic atmospheric acoustic waves. I did get the device to the point of working (quite well) and I have posted an article about it on my Bell Jar Web page at http://www.tiac.net/users/shansen/ belljar/microbar/. In the article I go over some of the basics of infrasound and acoustic waves, the principles of the instrument, the construction of my version of the instrument, and references for further reading. Also included are sketches of the instrument and a couple plots from the test runs. Building and initial testing are one thing. The next steps are to work on wind noise reduction and continuous data recording. I do have it connected to a pc that has a 711s card and SDR. Seems to work quite well. On a related topic, when my power came back on (I live in NH and we lost power for close to a half week) I saw a couple mentions of the AGU. For amateur seismologists, a membership in the AGU will be useful. It's only about $26 per year and it allows access to a lot of information. The journals are quite technical and pricey but the AGU also has many good books and several more modestly priced summary journals. For a sampler, check the AGU's site at www.agu.org. Comments and questions on the microbarograph are welcome. Steve Hansen _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ct@....... (Charlie & Terri Thompson -- Buda MicroRanch ) Subject: Teledyne Brown Geotechnical Corp Date: Fri, 13 Dec 1996 20:24:12 -0600 Here's the URL for Teledyne Brown Geotech...interesting seismic stuff! http://www.tbe.com/tech-pubs/products/geotech/geotech.html >The Geotechnical Corp. was renamed to Teledyne Geotech and is now called Teledyne Brown Engineering. It is >located in Garland, TX and the phone number is 214-343-7626. > >Their seismic instruments webpage is at www.tbe.com/products/instrument.html > >hope this helps. > >Bob Hammond, APSN, Fairbanks,AK > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: George Bush Subject: Re: Geotechnical Corp Date: Fri, 13 Dec 1996 18:29:42 -0800 (PST) At 02:08 PM 12/13/96 -0900, you wrote: >The Geotechnical Corp. was renamed to Teledyne Geotech and is now called Teledyne Brown Engineering. It is >located in Garland, TX and the phone number is 214-343-7626. > >Their seismic instruments webpage is at www.tbe.com/products/instrument.html > >hope this helps. > >Bob, thanks for the help. I knew I was beating my head against a wall, but I didn't realize that it was not even the right wall! I will check the URL as soon as I send this. I am very new to this. I have been monitoring for about a month, and so far have observed the big quake off of Peru, and some 4.0's from the Geisers, about 40 miles away. I live on the ocean coast north of San Francisco about 100 miles, and I get a lot of background noise from the surf, especially when it storms. Thanks again- George _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Darrell Collins Subject: Re: please help LP seismom. Date: Fri, 13 Dec 1996 20:23:59 -0700 (MST) All, I have thought that a list of what is available in everyone's reference library would be a fine source of help, so.... I have the Operation and Maintenance Manual for: Geotech Long Period Horizontal Seismometer Model 8700A Geotech Melton Vertical Seismometer Model 10012 Drop me E-Mail if you need copies. Does anyone know of a source of the flexure springs used in these instruments? My Melton has one broken, and its replacement would make it operational again. Darrell At 02:20 PM 12/13/96 -0800, you wrote: >Bob Barns wrote: > >>It would be helpful if people on this net would report details of >commercial >instruments. > >Yes, I agree, and was just about to make the same request myself. I have a >fine old surplus seismometer that really works great, but I would like to >know more about it. I hope some people on this net can help me with any >information on a seismometer made by: > > Geotechnical Corp. > Garland Texas > Model 8700C > Serial 70 > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: shansen@........ (shansen) Subject: Update on the Microbarograph - clarification on URL Date: Fri, 13 Dec 1996 22:41:43 -0500 (EST) The URL should have read: http://www.tiac.net/users/shansen/belljar/microbar.htm Steve _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ERMAIL@....... Subject: A/D interface Date: Sat, 14 Dec 1996 05:26:09 -0500 I am assuming this is getting to your list. Please forward if appropiate. I received information on an A/D to serial interface for $49. It accepts ASCII commands and has I/O, frequency, events and more. I have no experence with it but a data sheet is available at www.micromint.com The product is called AnswerMan. Dave ERmail@....... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Steve Hammond Subject: Re: Geotechnical Corp Date: Sat, 14 Dec 1996 10:13:13 -0800 (PST) On Fri, 13 Dec 1996, George Bush wrote: > At 02:08 PM 12/13/96 -0900, you wrote: > > I am very new to this. I have been monitoring for about a month, and so far > have observed the big quake off of Peru, and some 4.0's from the Geisers, > about 40 miles away. I live on the ocean coast north of San Francisco about > 100 miles, and I get a lot of background noise from the surf, especially > when it storms. > > Thanks again- George That puts you on top of the San Andreas at Salt Point? Where are you located at? Regards, Steve Hammond PSN BBS San Jose 408-226-0675 _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Seismometer Design Date: Wed, 18 Dec 1996 15:07:32 -0800 Greetings , All-- I've got a first-pass force balance seismometer working, using a Lehman mechanical design and a light-beam position detector. It's pretty neat to see it center itself when you apply power to the electronics, even without any fine leveling. As a closed-loop system, it is frequency response is pretty flat over the range of 0.05Hz to 10Hz, as measured using the setup posted to this list by Robert Barns on 12 Sep 96. I am having some problems with the amount of noise in the position detector, however. Right now, the noise is in the range of 100 nanometer or so. It has two light beams that are interrupted by a metal flag connected to the mass. When the mass moves, it covers one of the beams while it uncovers the other. The circuit then amplifies the difference between the two light beams. It has a sensitivity of about 7.6E-6 meters/volt. Does anyone have any suggestions / experience with these types of detectors, or others for that matter, that might work better than this. If I can't get this to work better, I'll probably look into the light beams to compensate for mis-leveling of the base, and a magnet/coil system to detect movement. Thanks, and Merry Christmas Karl Cunningham La Mesa, CA. karlc@......... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Seismometer Design Date: Wed, 18 Dec 1996 17:01:25 -0700 Karl- Pretty cool! > I've got a first-pass force balance seismometer working, using a Lehman > mechanical design and a light-beam position detector. It's pretty neat to > see it center itself when you apply power to the electronics, even without > any fine leveling. As a closed-loop system, it is frequency response is > pretty flat over the range of 0.05Hz to 10Hz, as measured using the setup > posted to this list by Robert Barns on 12 Sep 96. -Edward -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon Subject: Re: Seismometer Design Date: Wed, 18 Dec 96 19:38:28 -0500 Karl, You beat me to it. This is about the system I have been trying to assemble. Getting moved and setup in our home has prevented much work so far. One of the analog designers at work warned me about possible noise problems with this type of sensor. I assume you have the two photo transistors connect to the differential inputs of an op amp? Some things come to mind. Ordinary OP amps have a lot of 1/f noise that could be causing you problems. If you aren't already take a look at using a switched capacitor amplifier. Some of these have an order of magnitude lower 1/f noise than a conventional op amp. Make sure the LED's are well bypassed. Use fairly low values for the pullup resistors on the photo transistors. I don't have any idea of the relative noise of various photo detectors but PIN photo diodes might offer less noise. In my system I plan to connect the output of the sensor directly to the input of a 24 bit sigma delta converter eliminating the OP amp in the data path. The feedback electronics would be separate and heavily lowpassed so should not have the noise problem. I will use the switched capacitor OP amps also. Jim Hannon -------- REPLY, Original message follows -------- Date: Wednesday, 18-Dec-96 03:07 PM From: Karl Cunningham \ Internet: (karlc@.......... To: PSN \ Internet: (psn-l@.............. Subject: Seismometer Design Greetings , All-- I've got a first-pass force balance seismometer working, using a Lehman mechanical design and a light-beam position detector. It's pretty neat to see it center itself when you apply power to the electronics, even without any fine leveling. As a closed-loop system, it is frequency response is pretty flat over the range of 0.05Hz to 10Hz, as measured using the setup posted to this list by Robert Barns on 12 Sep 96. I am having some problems with the amount of noise in the position detector, however. Right now, the noise is in the range of 100 nanometer or so. It has two light beams that are interrupted by a metal flag connected to the mass. When the mass moves, it covers one of the beams while it uncovers the other. The circuit then amplifies the difference between the two light beams. It has a sensitivity of about 7.6E-6 meters/volt. Does anyone have any suggestions / experience with these types of detectors, or others for that matter, that might work better than this. If I can't get this to work better, I'll probably look into the light beams to compensate for mis-leveling of the base, and a magnet/coil system to detect movement. Thanks, and Merry Christmas Karl Cunningham La Mesa, CA. karlc@......... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) -------- REPLY, End of original message -------- _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Robert W. Teller" Subject: New Station Setup Date: Wed, 18 Dec 1996 19:33:17 -0700 Hello to All, I have acquired a 3 sensor station I am attempting to setup. It consists of 2 horizontal and 1 vertical GeoTech sensors, Larry's Amp/Filter and 12bit A/D boards. This will all be connected to a 40MHz 386 DX processor with 8MB RAM, 240MB HD running SDR. I have a few questions concerning the setup: 1. How far can I place the sensors from the Amp/Filter board, and how far from the Amp/Filer to the computer can I reliably operate? 2. Since I live in Montana, will putting the sensors in -40F temperatures hurt them? They will be inside a building on a concrete floor, but no heat source. I think this is enough for me to get started, if you have any suggestions and/or ideas please pass them on. They would be most appreciated! Thanks to all and a Merry Christmas, Bob Teller ------------------------------------------------ Montana Research Labs P.O. Box 977 Townsend, MT 59644 U.S.A. Tel 406-266-4483 email mrlabs@.......... web www.initco.net/local/mrlabs _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: New Station Setup Date: Wed, 18 Dec 1996 21:29:55 -0700 Bob- We, the USGS and the Canadian Earth Physics Branch, deployed Sprengnether DR100 portable autonomous digital seismographs (PADS) equipped with Sprengnether S-6000 three-component 2-Hz geophones (velocity sensors) in similar weather conditions in the boonies of northern New Brunswick, Canada, during the aftershock investigation of the 9 Jan 1982 Miramichi Earthquake there. The recorders were placed in some form of shelter, hut or parked vehicle, that was heated with a kerosene catalytic heater that kept the temperature above 0 degrees F, but the geophones were installed under snow and were frozen-stuck to the frozen soil and experienced temperatures of -30 C which is also about -30 F. At two of four these sites at which we operated the PADSs described above, we also operated a second colocated PADS equipped with a three-component force-balance accelerometer (FBA) sensor. We were very concerned that the cold temperatures would modify the response characteristics of either the sensors and/or the analog electronics of the recorders (not to mention screwing up the digital cassette tapes). However, the integrated acceleration (velocity) records agreed well (within 3 dB) with the directly recorded velocity records in both the frequency and time domains in the frequency band 2-50 Hz. Since the two signals were similar although derived from different sensors, we are confident that the PADS were functioning reliably. So it is very possible that you won't have a problem, but your concern is well-placed. You could do something like we did; you just need some good earthquakes. Good luck and Happy Holidays! -Edward Robert W. Teller wrote: > > Hello to All, > > I have acquired a 3 sensor station I am attempting to setup. It consists of > 2 horizontal and 1 vertical GeoTech sensors, Larry's Amp/Filter and 12bit > A/D boards. This will all be connected to a 40MHz 386 DX processor with 8MB > RAM, 240MB HD running SDR. I have a few questions concerning the setup: > > 1. How far can I place the sensors from the Amp/Filter board, and how far > from the Amp/Filer to the computer can I reliably operate? > > 2. Since I live in Montana, will putting the sensors in -40F temperatures > hurt them? They will be inside a building on a concrete floor, but no heat > source. > > I think this is enough for me to get started, if you have any suggestions > and/or ideas please pass them on. They would be most appreciated! > > Thanks to all and a Merry Christmas, > > Bob Teller > ------------------------------------------------ > > Montana Research Labs > P.O. Box 977 > Townsend, MT 59644 > U.S.A. > > Tel 406-266-4483 > email mrlabs@.......... > web www.initco.net/local/mrlabs > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Larry Cochrane Subject: Re: New Station Setup Date: Wed, 18 Dec 1996 20:36:41 -0700 At 07:33 PM 12/18/96 -0700, you wrote: >Hello to All, > >I have acquired a 3 sensor station I am attempting to setup. It consists of >2 horizontal and 1 vertical GeoTech sensors, Larry's Amp/Filter and 12bit >A/D boards. This will all be connected to a 40MHz 386 DX processor with 8MB >RAM, 240MB HD running SDR. I have a few questions concerning the setup: > >1. How far can I place the sensors from the Amp/Filter board, and how far >from the Amp/Filer to the computer can I reliably operate? Normally the Amp/Filter board should be within a few feet from the sensor. It depends on the impedance of the sensor. A sensor that has a output resistance (impedance) above around 1k (like a Lehman with a high turn count coil) should not drive more then 10 feet of shielded audio or coax cable. Commercial sensor may have a lower impedance and can drive more cable. The output of my amp/filter board can drive more then 100 feet of coax cable. > >2. Since I live in Montana, will putting the sensors in -40F temperatures >hurt them? They will be inside a building on a concrete floor, but no heat >source. Can't help you on the sensors. -40F sure is cold.... Since the amp/filter board needs to be near the sensor I would also worry about it. I never tested my board at this temperature. I don't have anything that will go that cold! You might have to make a little chamber for both the sensors and electronics and add some heat when it gets that cold. > >I think this is enough for me to get started, if you have any suggestions >and/or ideas please pass them on. They would be most appreciated! >Thanks to all and a Merry Christmas, Same to you and everyone on the list! Regards, Larry Cochrane Redwood City, PSN _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ct@....... (Charlie & Terri Thompson -- Buda MicroRanch ) Subject: Re: New Station Setup Date: Wed, 18 Dec 1996 22:43:26 -0600 Bob Teller writes: >Hello to All, > >I have acquired a 3 sensor station I am attempting to setup. It consists of >2 horizontal and 1 vertical GeoTech sensors, Larry's Amp/Filter and 12bit >A/D boards. This will all be connected to a 40MHz 386 DX processor with 8MB >RAM, 240MB HD running SDR. I have a few questions concerning the setup: > >1. How far can I place the sensors from the Amp/Filter board, and how far >from the Amp/Filer to the computer can I reliably operate? My PSN filter board is two feet from the sensor and is driving 100 feet of CATV coax to the A/D card...no problems with 60 Hz although you can see a small 10 Hz alias component in the FFT. 10 Hz is 60Hz-50Hz...50 Hz is the sample rate and the 60 Hz is some AC line pickup. > >2. Since I live in Montana, will putting the sensors in -40F temperatures >hurt them? They will be inside a building on a concrete floor, but no heat >source. Bob I recommend some sort of heater for the top side of the sensors. This problem relates to the slab being warmer than the air. The air in the bottom of the sensor housing needs to be cooler than at the top. This prevents air convection circulation that can cause "noise" in cold weather. We've been discussing this in the past if you happen to have read the postings about 1-2 months ago. A small appliance bulb placed near the top of the sensor housing is working for me...tonight it is 17 degrees here in Texas! >I think this is enough for me to get started, if you have any suggestions >and/or ideas please pass them on. They would be most appreciated! > >Thanks to all and a Merry Christmas, > >Bob Teller >------------------------------------------------ > >Montana Research Labs >P.O. Box 977 >Townsend, MT 59644 >U.S.A. > >Tel 406-266-4483 >email mrlabs@.......... >web www.initco.net/local/mrlabs > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ACole65464@....... Subject: Re: Seismometer Design Date: Thu, 19 Dec 1996 00:01:18 -0500 To Karl, I have been trying to get a simple force-feedback seismometer up and going for the last 15 months and was ready to throw in the towel when I came across some parts that I had used in a seismometer I had built some 12 years ago. Never throw out old parts you may always find a use for them eventually. I was using different types of phototransistors as the detectors for 15 months thinking that was the best thing to use, but I always had bad drift problems. I substituted the phototransistors with a pair of cheap Radio Shack photo-conductive resistors. The CdS cells worked right away. No noisy P-N junctions like phototransistors and diodes. I have two CdS cells hooked to +5vdc and their output legs tied to ground with a 1 K resitor. The two ouput legs are connected to the inputs of an OP-27 opamp via 10 K resistors. This opamp is configured as difference amplifier with 10X of gain. Its output signal along with some other parts provides the feedback signal to a coil on the pendulum. I used red LEDs as the light source aimed at each CdS, spaced about 1" away. A simple variable iris, half of which is attached to the pendulum and the other half covering half of the CdS cell. Note that I have two irises for the classic push-pull configuration. The pendulum is only 4" long hanging vertically as the S-G seismometer design, and has a 2.5 Hz natural frequency. The acceleration signal that is used for the seismic signal goes through a low pass filter with a corner frequency of .03 Hz. So the output of the filter gives a velocity signal that is flat from approx 2.5 Hz to .03 Hz. The pendulum moves +/-.010" to give a voltage signal of +/- 4.5 volts. It seems to be working fine, picking up lots of thermal noise coming through the concrete slab that it rests on, something that the conventional LP velocity seismometer never showed. The whole instrument is about 6" cube. I am planning now to build a vertical instrument in an air tight housing, maybe evacute it to see the difference in sensitivity and motorize the spring suspension mechanism to remotely compensate for spring sag. This is going to be a fun project! I hope that this reply will promote more replys from other readers. Merry Christmas to all the subscribers on the PSN. Allan Coleman _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Jim Hannon Subject: Re: New Station Setup Date: Thu, 19 Dec 96 06:08:24 -0500 I wouldn't worry too much about the cold. The worst thing likely to happen is some drift in gain. I design military electronics and test the stuff to -55 degrees C. More and more we can't get Mil parts so we have begun using commercial parts in our designs. It's the heat that is usually the problem. The other killer is the cycling of the temp up and down eventually breaks something. Jim Hannon _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Canadian seismic net Date: 19 Dec 96 10:55:20 EST Hi gang, Try www.seismo.emr.ca With your browser graphics turned on, click CNSN Hourly Plots. This gets about 40 simultaneous 'grams for a 1 hr. period all on one page. The 'grams are clipped so that they don't wipe out each other. I found it interesting to see what the pros have to work with. There is other interesting stuff at this URL. Bob Barns Berk. Hts., NJ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Robert W. Teller" Subject: Re: New Station Setup, Thanks Date: Thu, 19 Dec 1996 11:19:02 -0700 To all the kind people you responded to my request, Thank You very much! I am impressed with the speed, caliber and concern each of you showed me. Based on the responses, here is what I am going to attempt: 1. Place the sensors and Amp/Filter board into an enclosure with a simple, read light bulb, heat source. Will probably add a remote thermometer to see what kind of temperature swing I get. Perhaps some kind of thermostat. While a lot of you though the cold would not have a direct effect, the response from Jim Hannon pushed me over the edge to heat the environment. Larry also said he hadn't tested the Amp/Filter board at -40. (While the temperature in Montana doesn't stay get to -40 all the time, I have seen it stay below -30 for 10 days in a row.) 2. The sensors have 125 Ohm coils so driving them 150' or so shouldn't be a problem. I'm getting there folks! Can hardly wait until it's operational. Thanks again to everyone who helped! Merry Christmas, Bob Teller ------------------------------------------------ Montana Research Labs P.O. Box 977 Townsend, MT 59644 U.S.A. Tel 406-266-4483 email mrlabs@.......... web www.initco.net/local/mrlabs _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Canadian seismic net Date: Thu, 19 Dec 1996 15:46:30 -0700 Bob- > There is other interesting stuff at this URL. Slick dudettess and dudes, those Canadians. Thanks for the tip, I checked out the site. -Edward -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Meter-movement calibrator Date: 20 Dec 96 14:28:53 EST Karl Cunningham, I'm delighted to here of someone using the meter-movement calibrator. You are the first I've heard of. I would like to hear about any problems you had in getting this to work so that I could help others if questions arise. What did you use for an oscillator to drive the meter-movement down to below 0.05Hz? Your force balance system sounds very interesting. I hope you will describe it fully when you get it de-bugged. Some of us would like to try something similar, I'm sure. Jim Hannon's suggestion about 'switched capacitor amplifiers' got me to looking for them. I think that he's talking about what I know as 'chopper-stabilized' amps. There is a good discussion of these and other fancy amps starting on p 415 of Horowitz & Hill 'The Art of Electronics', 1989. I recently found some evidence of 1/f noise in my amp so I may try something better. Bob Barns _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@............... (John Lahr) Subject: Re: Computed Arrival Times Date: Fri, 20 Dec 96 17:38:16 PST John- How did make the calculator? with Java? -Edward ********* Edward, I wrote a pearl cgi script that gets the information from the user, calls finger quake and then calls a fortran program to get the arrival times for selected earthquakes. The basic pearl script was modified from one in a book on html. I'm just learning pearl. JCLahr _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Karl Cunningham Subject: Re: Meter-movement calibrator (a bit long) Date: Fri, 20 Dec 1996 21:13:57 -0800 Greetings, Bob -- Glad to be a user of your meter-movement calibrator. It was an ingenious idea you had to use a meter movement for a calibrated force generator. >I would like to hear about any problems you had in getting this to work so that >I could help others if questions arise. What did you use for an oscillator to >drive the meter-movement down to below 0.05Hz? I really didn't have any problems getting it to work. I used a 1mA movement out of some old piece of military electronics gear I got at a swap meet. I determined the current-to-force constant using a small piece of copper wire, as you suggested. I filed a very small v-shaped groove in the very end of the boom (Lehman-type device) and positioned the meter so that the round needle just fit into that groove: ___ ___ | \O/ | | V | Top View. The O represents the end of the meter needle. | | I imparted a slight tension in the needle by moving the meter stand (a portable vise) so as to keep the end of the needle pushed into the bottom of the groove. This prevented any backlash and I figured since the actual movement is so small, there would be almost no friction anyway. For a generator, I used a Wavetek function generator from work. It goes down to below one millihertz, so it's quite suited for this. On that subject, I saw a clever idea for an adjustable very-low frequency sine-wave generator: Use a 555 timer feeding a 10-bit or so digital binary counter of your favorite logic family. The output of this counter feeds the address inputs of an EPROM, the eight-bit output of which feeds the input of an 8-bit DAC. The EPROM is loaded with the proper codes (all four quadrants) to generate a sine wave at the output of the DAC. Feed this to an op-amp circuit with adjustable gain, and you have it. Just vary the 555 frequency to control the output frequency. Write a simple program (Basic, C, etc.) to generate the data for programming the EPROM. > Your force balance system sounds very interesting. I hope you will describe >it fully when you get it de-bugged. Be glad to. > Jim Hannon's suggestion about 'switched capacitor amplifiers' got me to >looking for them. I think that he's talking about what I know as >'chopper-stabilized' amps. There is a good discussion of these and other fancy >amps starting on p 415 of Horowitz & Hill 'The Art of Electronics', 1989. I >recently found some evidence of 1/f noise in my amp so I may try something >better. The company I work for makes chopper-stabilized amplifiers, although not exactly suited for this kind of work. These kind of amplifiers do have excellent low-frequency noise characteristics. I think if possible, it's better to build the equipment such that the basic transducer (force / movement -to-voltage) has an inherent high gain so that the voltage levels are up out of the mud. With today's op-amps, by the time you get to the 1/f noise level, the circuit also suffers from 60Hz pickup and other noise sources not directly related to the amplifiers. Karl Cunningham La Mesa, CA. karlc@......... _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Robert L Barns <75612.2635@..............> Subject: Quake of 12/10 8:36:18.3 Date: 22 Dec 96 11:35:55 EST Hi gang, Looking thru my quake recordings (from my 36 sec Lehman with a 0.1Hz LP filter) turned up a puzzler. It is of the central mid Atlantic ridge 12/10 8:36:18.3UTC, shallow, 0.8N 30.0W 6.2ms as reported by the USGS. It is in the psn.quake.net archives as 961210B.RLB. I did not find another recording of it there. It was 'Record of the Day' at www.gps.caltech.edu The distance from me was 6,280 km (3,904 mi.) or 56 deg. The great circle path is entirely under the ocean. Using WINQUAKE:If I set the S marker at the first pulse which is definately above noise and move the P marker around, I can get the org time and distance to agree nicely with the USGS and the SS seems obvious. The visibility of the P wave is less certain. (My times are about 7 secs. slow because of the delay in the filter.) Three puzzles arise:1. the S is largest phase. 2. the LQ and LR are not obvious. 3. There is a large phase between the S and where the LQ should be. The 'Record of the Day' looks normal. My recording of the N. Mid Atlantic ridge of 12/9 11:28:47 6.0 (1926 mi. from here, all-ocean path) is pretty normal--nice P, strong S. The LQ and LR are the biggest although the S is larger than I'm used to. Bob Barns Berkeley Hts., NJ _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Ken Navarre Subject: Comments on the LPT A/D convertor Date: Sun, 22 Dec 1996 08:44:17 -0800 (PST) Well, following the ad posted to the Usenet groups I ordered one of the 12 bit Adnav Electronics LPT Ver 2.0 analog-to-digital convertors for the parallel port. I was a bit disappointed when I discovered that it was a unipolar unit (0 - +2.5 vdc). The documentation did offer a simple circuit to create an offset. Being impatient I didn't bother with it and just shoved a 1.5 volt D cell in series with the output of one of Larry's telemetry boards. That and a 33k ohm resistor gave me a nice data trace with the center value at 1.25 volts and displayed in the center of the screen of my laptop running the software that came with the a/d plug. Yep. This will make a nice system to take on vacations to Mammoth and the Eastern Sierras! The A/D convertor is housed in a parallel port plug so it will run on most any PC with a printer port. Input is thru an attached female BNC connector. Power is supplied from the PC so no external power supply is needed. One drawback is that the full scale range is only 0 - 2.5 vdc. There is a STRONG warning in the documantation to not exceed voltages of -4 to +7 vdc. I can live with that... They have provided a a current limiting resisitor and a diode in the circuitry. They claim that this will cause some non-linearity in the data collection display and offer instructions for the removal of the componets if that creates a problem for your application. Removal will void the warranty, thou... The disk that comes with the unit has some data collection software and drivers. It only took a few minutes to get it running even without reading the instructions( Yes, it's a male thing...) The software is OK but I can hardly wait until Ted Blank adds the drviers for EMON!! That will make a great package for portable systems! I'll let you know how that progresses and where you can find the revised EMON software. Hopefully we will get it on the PSN sites. If you can't wait for that, the documetnation for the LPT 2.0 also describes the data acquistion and conversion process (all in 2 pages...) in case you want to create your own software. I don't! We'll need to let Larry take a look at the documentation. One part claims that, "another improvement that can be made is to eleminate the insertation of delay loops to control timing, and instead control the acquisition process from interrupts generated by hi-res hardware timing." sooooo, I'm wondering if this little creature can be made ot hop thru hoops and run SDR! Now, THAT would be spiffy!!! I love EMON for its ability to "go where no [seismo-freak] has gone before" but would rather be able to run something with color and a full screen hi-res display like SDR. Essientially, the 12 bit LPT A/D convertor is a simple way to get a portible system up and running. IT has a max acqusition rate of 18 samples/sec on my old "boat anchor" 286 laptop. While playing with it I watched a small event roll thru while it was running at 4.5 samples/sec and it was usable... All in all it ain't a bad deal for $60! I got mine in a couple of days following the order. The supplier is ADNAV ELECTRONICS 58 Chicory Cr. Lake Jackson, Tx., 77566 (409) 292-0988 and, yes, they do take Mastercard... Is anyone else running one of these critters??? Ken _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Computed Arrival Times Date: Sun, 22 Dec 1996 13:46:51 -0700 John- > I wrote a pearl cgi script that gets the information from What's pearl? Merry and Happy Whatever! -Edward -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Tobin Fricke" Subject: Re: Computed Arrival Times Date: Sun, 8 Dec 1996 12:56:15 -0800 > > I wrote a pearl cgi script that gets the information from > > What's pearl? I think he meant PERL, the Practical Extensions and Reporting Language. PERL is a really neat programming language that puts emphasis on functionality rather than structure and syntax. It's strengths are really in string manipulation. The PERL interpreter is available for nearly every computer/operating system type in existence for free. Try looking in Yahoo or at http://www.perl.com/ for more information. Tobin Fricke _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@............... (John Lahr) Subject: Re: Computed Arrival Times Date: Mon, 23 Dec 96 18:07:03 PST What's pearl? Merry and Happy Whatever! -Edward Edward, Pearl is a scripting language something like csh or tcsh. I know next to nothing about it, but unix-type people say it the best thing since sliced bread. Happy whatever to you too! JCLahr _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: lahr@............... (John Lahr) Subject: Re: Computed Arrival Times Date: Mon, 23 Dec 96 18:09:10 PST Tobin, Thanks for the info on PERL - as you noted, I can't even spell it! JCLahr _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Ken Navarre Subject: Re: New SDR version 1.8 Date: Mon, 23 Dec 1996 19:40:17 -0800 (PST) Larry, Just got the new version of SDR running. Looks great so far. Let you know if anything "glitches" (but I doubt it will!!!). Now, if you could only get his thing to run with that $60 A/D card... :( Ken On Mon, 23 Dec 1996, Larry Cochrane wrote: > Attached is the next version of SDR, this version has the following features > and/or changes: > > 1. You can now save PSN format event files greater then 65000 samples, the > limit is now 250,000 samples. This will allow you to save over 83 minutes of > data at 50 SPS. Too view event files over 65000 you must use WinQuake > version 2.3 or higher. > > 2. SDR can now be run at 50, 25, 10 or 5 samples per second. I recommend you > stay at 50 sps unless you have a very low low-pass filter on your system. > All channels are effected by this setting. Use the F5 key to change this > setting. > > 3. When SDR goes into an alarm one of the digital outputs will go high for > the duration of the alarm. See the SDR.TXT file for more information on what > output bit is set. > > 4. Each channel can now have a settings file other then CHANx.INI (x = 1 to > 4). This allows you to change channel settings easily by loading other setting > files. From: watson@................ (Charles Watson) Subject: Recent SRL, Ref to PSN & "Love Waves" Date: Tue, 24 Dec 1996 13:10:05 +0000 Two items of interest regarding the Seismology Research Letter, issue November/December 1996: 1) Steve Malone's Electronic Seismologist makes a positve reference to the "People's Seismograph Network". pp. 54 2) In reference to the Cassidy & Whitford article "Unusual "Love Waves" Recorded Above the Cascadia Subduction Zone", pp. 49, I'm sure this will spawn future field and lab monitoring. ;-) --- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: Recent SRL, Ref to PSN & "Love Waves" Date: Tue, 24 Dec 1996 16:55:49 -0700 Charles Watson wrote: > > Two items of interest regarding the Seismology Research Letter, issue > November/December 1996: > > 1) Steve Malone's Electronic Seismologist makes a positve reference to > the "People's Seismograph Network". pp. 54 > I agree: Steve- Courtesy of the PSN email mailing list, I was reminded to read your "Electronic Seismologist" article which is an excellent source of information about what the state of telemetry, realtime and "neartime" (near realtime) is in actuality as distinguished from my fantasies on the subject. I regret that I had not read the article before talking to you in person just after Thanksgiving. It's too bad that my own mental time tends more to the near rather than the real. What you need is some realtime method of disseminating your articles. Merry Whatever! -Edward > 2) In reference to the Cassidy & Whitford article "Unusual "Love Waves" > Recorded Above the Cascadia Subduction Zone", pp. 49, I'm sure this will > spawn future field and lab monitoring. ;-) But who is going to do the shake tests in the field? > --- > Charles P. Watson, Consulting Geologist > Advanced Geologic Exploration > Seismo-Watch / Earthquake Information Services > Voice: 702-852-0992 / Fax: 702-852-3226 > watson@................ > http://www.seismo-watch.com > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@............. with the body of the > message: leave PSN-L -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: "Wayne H. Francis" Subject: How can a Well be used? Date: Wed, 25 Dec 1996 13:52:40 -0800 To all: As newbie on this list I look forward to gathering the info I need to put together my own installation. However, a question doth arise: How can I best use my 150 foot well? It functions and is intended as part of my backup survival system (along with emergency generator, etc) when the "big one" hits, but mostly it sits unused. I read some time ago that someone was regularly measuring the water depth...that's doable, tho I wouldn't really know how to interpret a depth change (or rate of change)...besides, the well sometimes runs artesian after a wet winter here in SoCal. The real question is: does the 150 foot, 11 inch casing have any value as an "antenna" of sorts, and is there any validity to the idea of attaching a seismometer to the casing? This may set a new standard for "dumb question", of course, but as a ham operator I've pondered in the past the possibility of using the well as an antenna for low frequency waves...never really researched it very far, tho. Would appreciate the wisdom of the list on this. If the idea amounts to nothing, fine; but I don't want to miss an opportunity for a unique installation either. Any references I should go read? Thanks, Wayne Francis _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: David A Nelson Subject: seasons greetings Date: Thu, 26 Dec 1996 10:05:57 +1200 May you all have a very Merry Christmas, I trust the festive season is treating you well..... And may 1997 be more fruitful than 1996 was. Take Care Dave _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: frankcnd@.......... (Frank Condon) Subject: Re: seasons greetings Date: Wed, 25 Dec 1996 14:27:48 -0800 Same here and a Happy New Year too! Frank... > > May you all have a very Merry Christmas, I trust the festive season is >treating you well..... And may 1997 be more fruitful than 1996 was. > > Take Care Dave > > > >_____________________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email listserver@............. with the body of the >message: leave PSN-L > > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: nickishay@........ (Nicki Shay) Subject: Re: seasons greetings Date: Thu, 26 Dec 1996 07:18:39 EST Merry Christmas and a "Kool Yule" to you too, Dave. We hear snow is on its way... Nicki - From The Evergreen State of Washington! _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: cougercat@........... Subject: Re:Recent SRL, Ref to PSN & "Love Waves" Date: Sat, 28 Dec 96 00:48:12 PDT P> 1) Steve Malone's Electronic Seismologist makes a positve reference to P> the "People's Seismograph Network". pp. 54 P> P> 2) In reference to the Cassidy & Whitford article "Unusual "Love Waves" P> Recorded Above the Cascadia Subduction Zone", pp. 49, I'm sure this will P> spawn future field and lab monitoring. ;-) P> Where would I beable to get a copy of these articals/books? Thanks --Jeff Chang ******************************************* * mail from Jeff - cougercat@........... * ******************************************* _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: I'm from the government, I'm here to help you Date: Fri, 27 Dec 1996 16:12:18 -0700 -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". To my fellows who feel at risk (members of the GeoHazards Team): Last week, I inadvertantly sent a message to you all concerning my response to some objections to Phil Powers' use of animated figures on the GeoHazards website. I wrote: > Phil- > Well, you know what they say: > Those who can, do; > Those who can't, feel uptight and bitch defensively. > -Edward I wrote these remarks late Monday night while I was attempting to get all my day's email off of my "virtual desk" before I went home, and I thought that the message was going to Phil only; on Tuesday morning, I found out otherwise. I subsequently received some email from people who explained that there were some good, objective reasons for not having fancy, flashy, animated graphics. These reasons included the importance of the Team website looking "professional", the efficient use of system resources, and the need to maintain compatibility with primitive hardware and browsers that may used by the public and others. Well, first of all, I apologise to anyone who was offended by my rudeness. Second, I want to say that I include myself as one of "Those who can't", and consequently, "feel uptight and bitch defensively": my email reply does exactly that! At present, we are all being deluged by a digital wave -- the exponentially rapid proliferation of the Web and all its manifestations -- of unprecedented historical power and which has a time constant that is shorter than almost any other sociological phenomena ... almost seismic in its impact. Even the collapse of the Soviet Union, from which we are still reeling, proceeded much more slowly than the explosion of the Web. People such as myself with extensive computer experience (I have been programming for almost three decades) are suffering from the rapid development of cyberspace as much as people with little computer experience. Instead of being a machine used by the anointed to distance ourselves from the unanointed, the computer has been radically transformed into a medium which connects us all together, whether we like it or not: only the strong ground motions produced by large earthquakes are more democratic in their impact on the population. As I wrote in reply to someone who questioned my remarks quoted above: "There is a web world out there which we must either keep up with or be forgotten. Anything we can do to catch the attention of the web surfer is useful in getting her/him to see what we do and why that is sufficiently interesting to support. We don't get paid anymore to do secret things that nobody knows about." To which I received the response, ... "Or are you suggesting that we leave them in the dust?" The most recent issue of Eos (American Geophysical Union, Transactions) advertises the new AGU electronic journal, "Earth Interactions": http://EarthInteractions.org I checked it out and noticed that the browser they supply to read the sample article only supports PC platforms and does not support MAC or UNIX platforms at present (14 Dec 1996). That says something about the way the wind blows, and who is considered hip, or rather, "cool", and who is not; and who shall be left in the dust ... The situation we are in now is as if Jerry Garcia got together with the president of General Motors in the late Sixties, and they put together a plan to distribute Rock'n'Roll, LSD, and automobiles using the Interstate Highway System (which, in fact, was built ostensibly for National Defense). However, as we know now, GM then dropped the ball, and the kids (we) all bought VWs instead. Now, instead of Jerry and GM, we have Bill Gates, Al Gore, and Jim Barksdale (president and CEO of Netscape Communications): I'll let you work out who is the freakiest. I note that none of our computer staff has ever questioned the scientists about the kind of mathematics or statistics used to "forecast" the time of earthquakes, e.g., Parkfield, or to predict strong ground motions caused by earthquakes. In conclusion, perhaps the real problem that should be addressed at present is: What is the Geologic Hazard of Virtual Reality? -Edward -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". From: watson@................ (Charles Watson) Subject: Re: Recent SRL, Ref to PSN & "Love Waves" Date: Sat, 28 Dec 1996 07:47:06 +0000 cougercat@........... wrote: > > P> 1) Steve Malone's Electronic Seismologist makes a positve reference to > P> the "People's Seismograph Network". pp. 54 > P> > P> 2) In reference to the Cassidy & Whitford article "Unusual "Love Waves" > P> Recorded Above the Cascadia Subduction Zone", pp. 49, I'm sure this will > P> spawn future field and lab monitoring. ;-) > P> > > Where would I beable to get a copy of these articals/books? Jeff, Hook into this URL: http://www.seismosoc.org/ssa/ for the address and phone number of the Seismological Society of America. SSA publishes Seismological Research Letters six times per year. The Volume in reference is: Vol. 67, No. 6. BTW: I have it from good reference that the Steinbrugge cassette tape "Earthquake Related Sounds" does not contain an audio track of the "Unusual Love Waves..." ;-) Charles --- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Hammonds Subject: Re: I'm from the government, I'm here to help you Date: Sat, 28 Dec 1996 07:30:05 -0900 (AST) Edward, I read with great interest your email to the PSN mailing list concerning the "flashy" nature of webpages and the need to serve the public the best way possible. At least, I think that's what you were saying. Tell me, are there people at NEIC saying that an attractive webpage is NOT professional? In my opinion, we (USGS) need to get rid of the typical "government look" of any publication, be it electronic or printed. Flashy animated figures on a web- page can enhance the reader's ability to understand the story being told. Animation is attractive. Aren't we of the Survey trying to be more attractive? The quality of science is not diminished by being attractive! Look what Carl Sagan did for astronomy by making it attractive. Robert Ballard has made oceanography "cool" because he made it, yes, attractive. The way I see it, as scientists, we are always looking for better tools with which to do our jobs. Web graphics and animation are better tools to get the results of our work to the public who pay our salaries! "Illegitimi non carborundum" regards, Bob Hammond (at home) (USGS, Fairbanks, AK (bhammond@.......... At 16:12 12/27/96 -0700, you wrote: >-- >Edward Cranswick Tel: 303-273-8609 >US Geological Survey, MS 966 Fax: 303-273-8600 >1711 Illinois St cranswick@........ >Golden, CO 80401 USA E.M. Forster said, "Only connect". >Message-ID: <32B32BEA.139E@..................> >Date: Sat, 14 Dec 1996 15:36:26 -0700 >From: Edward Cranswick >Organization: US Geological Survey >X-Mailer: Mozilla 3.0Gold (Win95; I) >MIME-Version: 1.0 >To: geo_haz_team@.................. >Subject: [Fwd: Re: Opinion on animated images on home web page] >Content-Type: multipart/mixed; boundary="------------169F68952FE" > >-- >Edward Cranswick Tel: 303-273-8609 >US Geological Survey, MS 966 Fax: 303-273-8600 >1711 Illinois St cranswick@........ >Golden, CO 80401 USA E.M. Forster said, "Only connect". >Message-ID: <32B32AD3.6B4D@..................> >Date: Sat, 14 Dec 1996 15:31:47 -0700 >From: Edward Cranswick >Organization: US Geological Survey >X-Mailer: Mozilla 3.0Gold (Win95; I) >MIME-Version: 1.0 >To: Philip Powers >Subject: Re: Opinion on animated images on home web page >References: <1.5.4.32.19961209185746.00680134@..................> >Content-Type: text/plain; charset=us-ascii >Content-Transfer-Encoding: 7bit > >To my fellows who feel at risk (members of the GeoHazards Team): > >Last week, I inadvertantly sent a message to you all concerning my >response to some objections to Phil Powers' use of animated figures on >the GeoHazards website. I wrote: > >> Phil- >> Well, you know what they say: >> Those who can, do; >> Those who can't, feel uptight and bitch defensively. >> -Edward > >I wrote these remarks late Monday night while I was attempting to get >all my day's email off of my "virtual desk" before I went home, and I >thought that the message was going to Phil only; on Tuesday morning, I >found out otherwise. > >I subsequently received some email from people who explained that there >were some good, objective reasons for not having fancy, flashy, animated >graphics. These reasons included the importance of the Team website >looking "professional", the efficient use of system resources, and the >need to maintain compatibility with primitive hardware and browsers that >may used by the public and others. > >Well, first of all, I apologise to anyone who was offended by my >rudeness. Second, I want to say that I include myself as one of "Those >who can't", and consequently, "feel uptight and bitch defensively": my >email reply does exactly that! At present, we are all being deluged by >a digital wave -- the exponentially rapid proliferation of the Web and >all its manifestations -- of unprecedented historical power and which >has a time constant that is shorter than almost any other sociological >phenomena ... almost seismic in its impact. Even the collapse of the >Soviet Union, from which we are still reeling, proceeded much more >slowly than the explosion of the Web. > >People such as myself with extensive computer experience (I have been >programming for almost three decades) are suffering from the rapid >development of cyberspace as much as people with little computer >experience. Instead of being a machine used by the anointed to distance >ourselves from the unanointed, the computer has been radically >transformed into a medium which connects us all together, whether we >like it or not: only the strong ground motions produced by large >earthquakes are more democratic in their impact on the population. > >As I wrote in reply to someone who questioned my remarks quoted above: >"There is a web world out there which we must either keep up with or be >forgotten. Anything we can do to catch the attention of the web surfer >is useful in getting her/him to see what we do and why that is >sufficiently interesting to support. We don't get paid anymore to do >secret things that nobody knows about." To which I received the >response, ... "Or are you suggesting that we leave them in the dust?" > >The most recent issue of Eos (American Geophysical Union, Transactions) >advertises the new AGU electronic journal, "Earth Interactions": > http://EarthInteractions.org >I checked it out and noticed that the browser they supply to read the >sample article only supports PC platforms and does not support MAC or >UNIX platforms at present (14 Dec 1996). That says something about the >way the wind blows, and who is considered hip, or rather, "cool", and >who is not; and who shall be left in the dust ... > >The situation we are in now is as if Jerry Garcia got together with the >president of General Motors in the late Sixties, and they put together a >plan to distribute Rock'n'Roll, LSD, and automobiles using the >Interstate Highway System (which, in fact, was built ostensibly for >National Defense). However, as we know now, GM then dropped the ball, >and the kids (we) all bought VWs instead. Now, instead of Jerry and GM, >we have Bill Gates, Al Gore, and Jim Barksdale (president and CEO of >Netscape Communications): I'll let you work out who is the freakiest. > >I note that none of our computer staff has ever questioned the >scientists about the kind of mathematics or statistics used to >"forecast" the time of earthquakes, e.g., Parkfield, or to predict >strong ground motions caused by earthquakes. > >In conclusion, perhaps the real problem that should be addressed at >present is: >What is the Geologic Hazard of Virtual Reality? > >-Edward > >-- >Edward Cranswick Tel: 303-273-8609 >US Geological Survey, MS 966 Fax: 303-273-8600 >1711 Illinois St cranswick@........ >Golden, CO 80401 USA E.M. Forster said, "Only connect". > _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Re: I'm from the government... Date: Sat, 28 Dec 1996 09:25:21 +0000 Hammonds wrote: > > Edward, > > Aren't we of the Survey trying to be more attractive? > The quality of science is not diminished by being attractive! Look what > Carl Sagan did for astronomy by making it attractive. Robert Ballard has made > oceanography "cool" because he made it, yes, attractive. > ...and Seismo-Watch for seismology! :-) BTW: Put together a summary page of the television panels I've been doing for my local community access station: http://www.seismo-watch.com/EQSERVICES/CurrentActivity/WER.html I recently added a "Seismic Report" panel which comes on after eaach Global or Regional map and describes a few bullet items about the activity. I think these came out quiet well and adds a new dimention to the sequence. At some point, I will have to learn the video technique, as well as Java and QuickTime for the web. MacroMedia liked what I was doing and gave me a copy of Director to provide the annimation, but with all the things happening at once, I haven't had the time to learn ANOTHER piece of software. Hey, anyone out there know how to opporate Director? Charlie --- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: mgray1@................ (Mike Gray) Subject: Re: I'm from the government... Date: Sat, 28 Dec 1996 21:10:59 -0600 Most web page designers worth their salt will include a link from the home page to pages that are more text based for the computer/software/bad phone lines/internet-costs-too-much challenged. Flashy pages are great for some, but there are many that can't make use of them for one or more reasons. It's like Reader's Digest printing only in small print. There are people that need the large print. At the other end of a spectrum, there are people that will plunk down $35,000 or more for a car and not bat an eyelash about the cost. There are people that need less expensive transportation. There's a "market" out there for both browser situations and, as easy as it is to accomodate both, it does not behoove anyone to ignore either one. Mike Gray MO Bureau of Emergency Medical Services (Dept of Health) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: ACole65464@....... Subject: Who reads the PSN and lives in Seattle? Date: Thu, 26 Dec 1996 23:21:04 -0500 To those living in the greater Seattle area and beyond, It appears from time to time that there are numerous individuals that live here, in God's country, who are interested in amateur seismology. Have we come to that point in time to form our very own NW chapter of amateur seismologists? This may be a good opportunity to share ideas and possibly show off the contraptions (instruments) that some of us have made over the years. I would be interested in helping to arrange for such an event. Just a very informal once a year get together. Allan Coleman _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: rond@................ (Charlie Rond) Subject: Re: I'm from the government, I'm here to help you Date: Mon, 30 Dec 1996 02:54:27 -0600 Edward, Regardless of your original exchange - a bit of applause from out here in the boonies for your Web site animation followup. I thought your response frankly provocative and articulate in its analysis of the impact technology is having upon those of us trying to ride it. Stay the course - and Happy New Year!... Charlie Rond -\/\--Public Seismic Network-Memphis rond@................ (901) 360-0302 [ free BBS ] http://gandlf.ceri.memphis.edu/~rond http://gandlf.ceri.memphis.edu/~rond/psn _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: Edward Cranswick Subject: Re: I'm from the government... Date: Mon, 30 Dec 1996 12:26:36 -0700 Charlie- I forwarded your first announcement about "Seismic Report" to the Chief Scientist here, Randy Updike, shortly after you sent it to the PSN on 11/22/96. I have never got a response. > BTW: Put together a summary page of the television panels I've been > doing for my local community access station: > > http://www.seismo-watch.com/EQSERVICES/CurrentActivity/WER.html > I am going to send him this announcement too. -Edward -- Edward Cranswick Tel: 303-273-8609 US Geological Survey, MS 966 Fax: 303-273-8600 1711 Illinois St cranswick@........ Golden, CO 80401 USA E.M. Forster said, "Only connect". _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) From: watson@................ (Charles Watson) Subject: Re: I'm from the government... Date: Mon, 30 Dec 1996 14:41:07 +0000 Well, thanks for your comments Ed. Randy's achievements are well respected and I welcome his response. I like to think I am making progress in the transfer of information. I know more people understand their regional and global earthquake activity better because of Seismo-Watch. I have been able to break into media markets that were unavailable for this kind of information in the past. I expect to make significant strides again in 1997 as many new markets present themselves. The way the Seismo-Watch television series developed is curious, one I should tell you some time, but I believe I have discovered an interesting method of conveying the information both economically and effectively. It has the potential to bringing current earthquake information into highly visible arena. Seismo-Watch is a fun project, one that has a win-win proposition. I look forward to new opportunities that bring new resources and associations. --- Charles P. Watson, Consulting Geologist Advanced Geologic Exploration Seismo-Watch / Earthquake Information Services Voice: 702-852-0992 / Fax: 702-852-3226 watson@................ http://www.seismo-watch.com _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L)